identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
8216B8D6441E582F8C4A6246820A53C0.text	8216B8D6441E582F8C4A6246820A53C0.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete fumida Spirin & Ryvarden 2026	<div><p>Adustochaete fumida Spirin &amp; Ryvarden sp. nov.</p><p>Fig. 15 A</p><p>Holotype.</p><p>Zimbabwe • Masvingo: Chiredzi, Tambuti Lodge, corticated angiosperm branch, 17 Feb 1986, Ryvarden 23591 * (O, isotype – H) .</p><p>Etymology.</p><p>Fumidus (Lat., adj.) – ash-gray.</p><p>Description.</p><p>Basidiomata annual, effused, up to 5 cm in the longest dimension, arid, rather soft, 0.1–0.2 mm thick. Hymenial surface smooth, cream-colored to grayish, occasionally cracking. Margin sharply delimited, concolourous with hymenial surface, adnate, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or brownish, slightly to distinctly thick-walled, interwoven or subparallel, rather tightly arranged, 2–6 μm in diam., subhymenial hyphae predominantly hyaline, thin- to slightly thick-walled, ascending or interwoven, rather densely arranged and partly agglutinated, occasionally twisted, 2–4 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae, small, angular to sand-like. Cystidia very rare, thin-walled, single tubular-clavate or tapering and more or less distinctly swollen at the base, 20–23 × 5–8 μm, contents hyaline or grayish, CB +. Hyphidia hyaline, thin-walled, single or in groups of 3–4, with subfusiform or hyphoid stem, 18–42 × 2.5–5 μm, bearing several richly branched apical outgrowths, 0.5–1.2 μm in diam. at the very apex; apical branches encrusted by small, densely arranged crystals. Basidia four-celled, narrowly ellipsoid-ovoid to obconical, sessile, (15.5 –) 18–25 (– 26.5) × (8.9 –) 9.0–12.0 (– 12.5) μm (n = 25 / 1), thin-walled or with a distinct wall, usually embedded, occasionally with a reduced stalk-like base, up to 3 × 5 μm, sterigmata up to 30 × 3–4 μm. Basidiospores thin-walled, cylindrical, more or less clearly curved, (11.8 –) 12.1–18.1 (– 18.2) × (5.1 –) 5.2–6.3 (– 6.4) μm (n = 30 / 1), L = 15.96, W = 5.73, Q = 2.79.</p><p>Remarks.</p><p>This species is introduced here based on a single collection from Zimbabwe. Adustochaete fumida produces completely smooth basidiomata on thin branches of angiosperms. It differs from A. scalena, another smooth species from the same geographic area, in having lighter-coloured basidiomata and smaller basidia, as well as longer and distinctly narrower basidiospores. Microscopically, A. fumida is most similar to A. hiemalis from Europe. The latter species produces smaller, nearly white basidiomata on tiny plant remnants and its cystidia and basidia are larger than in A. fumida .</p></div>	https://treatment.plazi.org/id/8216B8D6441E582F8C4A6246820A53C0	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
6C109797D84E5511A6E4EF002C31A16D.text	6C109797D84E5511A6E4EF002C31A16D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete gloeoapicata Spirin & Malysheva 2026	<div><p>Adustochaete gloeoapicata Spirin &amp; Malysheva sp. nov.</p><p>Fig. 15 B</p><p>Holotype.</p><p>Mexico • Veracruz: Xalapa, Botanical Garden, dead corticated branches, 22 Sep 1985, Ryvarden 23269 * (O, isotypes – H, LE) .</p><p>Etymology.</p><p>Gloeoapicatus (Lat., adj.) – in reference to a resinous apical globule at the top of cystidia.</p><p>Description.</p><p>Basidiomata annual, effused, up to 10 cm in the longest dimension, arid, rather soft, 0.1–0.2 mm thick. Hymenial surface smooth, cream-colored to grayish, rarely irregularly cracking. Margin sharply delimited, first nearly white, then concolourous with hymenial surface, adnate, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or brownish, thin- to slightly thick-walled, subparallel, partly agglutinated, 2–5 μm in diam., subhymenial hyphae hyaline or brownish, thin-walled, interwoven, rather densely arranged and partly agglutinated, 1.5–4 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Cystidia (gloeocystidia) abundant, thin- to distinctly thick-walled, single or in groups of 3–4, more or less clearly tapering, often distinctly swollen at the base, 22–52 × 6–14 μm, contents brownish to grayish-brown, strongly CB +; some cystidia bearing resinous-brown, CB + apical globule, up to 15 μm in diam. Hyphidia hyaline or more rarely brownish, thin- to slightly thick-walled, single or in groups of 3–4, with subfusiform or hyphoid stem, 17–34 × 3–5 μm, bearing several richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex; apical branches encrusted by small, densely arranged crystals. Basidia four-celled, narrowly ellipsoid-ovoid to nearly obconical, sessile, (14 –) 14.5–20 (– 21) × (8.4 –) 9.0–11.0 (– 11.2) μm (n = 20 / 2), thin-walled, mostly embedded, occasionally with a reduced stalk-like base, up to 3 × 3 μm, sterigmata up to 20 × 3–3.5 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, slightly or moderately curved, (10.0 –) 10.2–14.1 (– 14.3) × (4.8 –) 5.0–6.2 (– 6.3) μm (n = 60 / 2), L = 11.68–12.63, W = 5.51–5.53, Q = 2.12–2.29.</p><p>Remarks.</p><p>Adustochaete gloeoapicata is described here as the single smooth species of the genus known to occur in North America. It has so far only been collected twice in the same locality in Veracruz, Mexico. Adustochaete gloeoapicata differs from other smooth species of the genus in having large, basally swollen gloeocystidia which sometimes bear an apical resinous globule. No such cystidia are known to us for any other representative of the Auriculariales .</p></div>	https://treatment.plazi.org/id/6C109797D84E5511A6E4EF002C31A16D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
DFC421925F7E551186E7B465E65644F2.text	DFC421925F7E551186E7B465E65644F2.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete hiemalis Spirin 2026	<div><p>Adustochaete hiemalis Spirin sp. nov.</p><p>Figs 15 C, 16 A, 17</p><p>Holotype.</p><p>Sweden • Västergötland: Mölndal, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=11.98129&amp;materialsCitation.latitude=57.67614" title="Search Plazi for locations around (long 11.98129/lat 57.67614)">Snöhöjdsliden</a>, 57.67614; 11.98129, Rubus fruticosus s. lato (dead stem on the ground), 16 Dec 2024, Spirin 17997 * (GB, isotype – H) .</p><p>Etymology.</p><p>Hiemalis (Lat., adj.) – wintry, hibernal.</p><p>Description.</p><p>Basidiomata annual, effused, patch-like, usually very small, a few mm in diam., rarely larger, up to 1 cm in the widest dimension, arid, pellicular and very soft, 0.05–0.2 mm thick, finally degrading to a white crumbling mass. Hymenial surface smooth, nearly white or cream-colored. Margin first pruinose, adnate, then rather sharply delimited and partly detaching, white, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, thin- to slightly thick-walled, loosely interwoven or subparallel, 1.5–4 μm in diam., frequently anastomosing, subhymenial hyphae hyaline, thin- to slightly thick-walled, ascending or interwoven, spaced, 1–4 μm in diam. Crystals abundant in all parts of basidiomata, often encrusting hyphae, small, angular to sand-like. Cystidia occasionally present, hyaline, thin-walled, single or in groups of 2–3, distinctly tapering or clavate, 18–57 × 5–12.5 μm, some with grayish-brown, distinctly CB + contents. Hyphidia thin- to slightly thick-walled, often in groups of 2–4, with a cystidia-like, narrowly fusiform or hyphoid, hyaline or brownish stem, 20–40 × 2–8 μm, bearing several richly branched apical outgrowths, 1–2 μm in diam. at the very apex; apical branches encrusted by small, densely arranged crystals. Basidia four-celled, ellipsoid-ovoid to nearly obconical, sessile, (16 –) 17–31 (– 32) × (9.3 –) 9.6–13.5 (– 13.6) μm (n = 50 / 3), often with a distinct wall, embedded or exposed, rarely with a reduced stalk-like base, up to 4 × 3 μm, sterigmata up to 27 × 3–3.5 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, more or less clearly curved, (9.2 –) 9.8–17.8 (– 18.4) × (4.8 –) 4.9–6.4 (– 6.8) μm (n = 65 / 3), L = 12.90–15.00, W = 5.68–5.88, Q = 2.27–2.64.</p><p>Remarks.</p><p>Adustochaete hiemalis is the only representative of the genus known to occur in Europe. It produces minuscule, whitish, smooth basidiomata on thin dead stems of shrubs ( Lavandula, Rubus) and lianas ( Clematis) and, according to our observations, fruits from December to June. Morphologically, it is very similar to other smooth Adustochaete spp. known from tropical areas. One specimen of A. hiemalis was collected from a Lavandula stem which it occupied together with Proterochaete letendreana . The latter species occasionally produces nearly white, small basidiomata on shrub or grass stems which are superficially very similar to A. hiemalis . In these cases, the species can be recognized after careful morphological study. Basidiomata of A. hiemalis are softer than those of P. letendreana, and they consist of rather loosely arranged, spaced (not agglutinated) hyphae. Moreover, A. hiemalis possesses cystidia and its basidia are larger than in P. letendreana . Basidiospores of both species are nearly identical and quite variable in size. See further remarks under P. letendreana .</p><p>Leiostroma farinellum rarely occurs on thin angiosperm branches and can be mistaken for A. hiemalis, too. It can be separated from the latter species due to grayish basidiomata, the lack of cystidia, smaller basidia and more extensive, sometimes solid crystalline encrustation on hyphae and hymenial cells.</p></div>	https://treatment.plazi.org/id/DFC421925F7E551186E7B465E65644F2	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
9725B022BF905AFA8723674317E7B365.text	9725B022BF905AFA8723674317E7B365.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete minuta (Pat.) Spirin & Viner 2026	<div><p>Adustochaete minuta (Pat.) Spirin &amp; Viner comb. nov.</p><p>Fig. 15 D</p><p>= Heterochaete minuta Pat., Bulletin de la Société Mycologique de France 9: 139, 1893. Holotype. Ecuador. Pichincha: Quito, Pululahua, twigs on the ground, Feb 1892, Lagerheim (FH) .</p><p>Description.</p><p>Basidiomata annual, effused, up to 5 cm in the longest dimension, arid, rather soft, 0.05–0.1 mm thick. Hymenial surface spinulose, grayish, spines irregularly or evenly distributed, sharp-pointed, 70–150 × 30–60 μm, 6–8 (9) per mm. Margin floccose, clearly delimited, first white, then grayish, adnate, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, slightly to distinctly thick-walled, interwoven or subparallel, rather loosely arranged, 1.5–4 μm in diam., subhymenial hyphae hyaline, thin-walled, interwoven, 1.5–3 μm in diam., hyphae of hymenial spines hyaline or brownish, thin- to slightly thick-walled, ascending, in older parts agglutinated and cemented by amorphous brown substance, CB (+) to CB +, 1.5–3 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Cystidia rare, hyaline, thin-walled, more or less clearly tapering, often sinuous, more rarely clavate, 17–30 × 4.5–9 μm. Hyphidia hyaline, thin- to slightly thick-walled, with a hyphoid or subfusiform-clavate stem, 15–34 × 2–6 μm, bearing several richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex; apical branches covered by continuous crystalline encrustation. Basidia four-celled, ellipsoid-ovoid to nearly obconical, sessile, (14 –) 14.5–20 (– 21.5) × (9.0 –) 9.2–12.4 (– 13.3) μm (n = 50 / 4), with a distinct wall, mostly exposed, rarely with a reduced stalk-like base, up to 4 × 3 μm, sterigmata up to 20 × 3–3.5 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, more rarely narrowly cylindrical, often clearly curved, (10.3 –) 10.7–18.1 (– 18.2) × (5.0 –) 5.1–6.3 (– 6.7) μm (n = 120 / 4), L = 13.18–15.28, W = 5.62–5.86, Q = 2.27–2.73.</p><p>Remarks.</p><p>This species was originally described as Heterochaete minuta by Patouillard and Lagerheim (1893) from Pululahua, Ecuador. It was subsequently redescribed by Bodman (1952), and her reintroduction of H. minuta fits well with three specimens from Argentina and Mexico studied by us. The only discordant feature mentioned in the protologue is the longer spines, measured as 200–450 μm long, i. e. clearly longer than in all our collections. Currently, it is impossible to determine whether H. minuta s. typi represents a similar species not conspecific with our material or the type material is a more developed specimen than those studied by us. This question can be answered only after getting sequenced material from the type locality. Morphologically and phylogenetically, A. minuta is very close to A. nivea (see below). It differs from the latter species in having smaller cystidia, as well as longer and slightly narrower basidiospores.</p></div>	https://treatment.plazi.org/id/9725B022BF905AFA8723674317E7B365	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
D99900F80113563E9B0C8A4F7609E136.text	D99900F80113563E9B0C8A4F7609E136.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete nivea R. L. M. Alvarenga	<div><p>Adustochaete nivea R. L. M. Alvarenga in Hyde et al., Fungal Diversity 100: 255, 2020</p><p>Fig. 15 E</p><p>Holotype.</p><p>Brazil • Pernambuco: Recife, Federal University of Pernambuco, 2018, Alvarenga 531 (URM 93408 *) .</p><p>Description.</p><p>Basidiomata annual, effused, up to 5 cm in the longest dimension, arid, rather soft, 0.05–0.1 mm thick. Hymenial surface spinulose, cream-colored to grayish, spines rather regularly distributed, sharp-pointed, 100–200 × 35–60 μm, 5–7 per mm. Margin pruinose, white to cream-coloured, adnate, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, slightly to distinctly thick-walled, variably inflated, interwoven or subparallel, loosely arranged, 1.5–4.5 μm in diam., subhymenial hyphae hyaline, thin- to distinctly thick-walled, interwoven, rather loosely arranged, 1–3 μm in diam., hyphae of hymenial spines hyaline, thin- to slightly thick-walled, ascending, 1.5–3 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Cystidia occasionally present, hyaline or grayish-brownish, thin- to distinctly thick-walled, more or less clearly tapering, often sinuous, 21–40 × 5.5–10 μm. Hyphidia hyaline, thin- to slightly thick-walled, with hyphoid, occasionally branched stem, 20–44 × 3.5–5.5 μm, bearing several richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex; apical branches richly encrusted by small, densely arranged crystals. Basidia four-celled, ellipsoid-ovoid to nearly obconical, sessile, (14 –) 14.5–18.5 (– 19) × (9.1 –) 9.2–12.0 (– 12.2) μm (n = 30 / 2), thin-walled, embedded or exposed, sterigmata up to 30 × 3–3.5 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, clearly curved, (10.2 –) 10.3–15.2 (– 15.9) × (5.0 –) 5.1–6.8 (– 7.2) μm (n = 64 / 2), L = 12.01–13.12, W = 5.93–6.02, Q = 2.03–2.18.</p><p>Remarks.</p><p>Here we reintroduce A. nivea based on our specimens from Argentina and Mexico. The sequence of the Argentinian collection is identical to that of the holotype from Brazil (Hyde et al. 2020). However, the protologue describes A. nivea as an acystidiate species with shorter and narrower basidiospores. More sequenced specimens of A. nivea are needed to understand its intraspecific variation. As redescribed here, A. nivea is a close relative of A. minuta . Their morphological differences are mentioned under the latter species.</p></div>	https://treatment.plazi.org/id/D99900F80113563E9B0C8A4F7609E136	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
B0D6C74F057B54819C6727677100FF9E.text	B0D6C74F057B54819C6727677100FF9E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete R. L. M. Alvarenga & K. H. Larss.	<div><p>Adustochaete R. L. M. Alvarenga &amp; K. H. Larss., Botany 97: 442, 2019</p><p>Description.</p><p>Basidiomata annual, effused, arid, nearly white to grayish or brownish. Hymenial surface smooth or spinulose. Hyphal structure monomitic; hyphae clamped, hyaline or brownish, spaced or partly agglutinated, basidia-bearing hyphae not differentiated. Crystals abundant, angular or sand-like. Cystidia as a rule present, clavate or tapering, in some species with brownish, cyanophilous contents (gloeocystidia). Hyphidia present, with a well-differentiated stem and richly branched, densely encrusted apical outgrowths. Basidia four-celled, ellipsoid-ovoid to nearly obconical, sessile, thin-walled or with a distinct wall, exposed or embedded, occasionally with a reduced stalk-like base. Basidiospores hyaline, thin-walled, narrowly to broadly cylindrical, curved. On dry or just fallen branches, more rarely on shrub stems of angiosperms.</p><p>Generic type.</p><p>Adustochaete rava R. L. M. Alvarenga &amp; K. H. Larss.</p><p>Adustochaete was described to encompass two Heterochaete - like species, A. rava and A. interrupta . These species turned out to be phylogenetically distant from the generic type of Heterochaete, H. andina, as well as other Heterochaete s. lato species reclassified among Eichleriella, Hirneolina, Heteroradulum, and Tremellochaete (Alvarenga et al. 2019), and were therefore placed in their own genus. Subsequently, four more species were introduced in Adustochaete, viz. A. nivea from Brazil (Hyde et al. 2020), as well as A. yunnanensis, A. albomarginata, and A. punctata from China (Li and Zhao 2022; Dong et al. 2024). Here we add six more species to the genus and reintroduce A. rava and A. nivea based on more extensive material from Argentina (for the species-level phylogeny of the genus, see Figs 13, 14). See also remarks on Exidia punctata under Excluded and insufficiently known species below.</p><p>Although Adustochaete spp. form a strongly supported clade (Figs 1, 2) and are clearly separated from the rest of the genera in the Exidia clade in our phylogenies, the morphological definition of Adustochaete is not easy. Originally, the genus was defined as containing monomitic, cystidia-bearing species with grayish or brownish, spinulose or tuberculate hymenial surface and four-celled, ellipsoid-ovoid or nearly obconical basidia which possess thick sterigmata (Alvarenga et al. 2019). However, expanding Adustochaete with more species described makes it difficult to maintain the original concept of the genus. In particular, adding four completely or nearly smooth species ( A. fumida, A. gloeoapicata, A. hiemalis, and A. scalena) blurs the borders between Adustochaete and some other genera containing the former Exidiopsis and Heterochaete spp.</p><p>Of them, the reinstated Leiostroma is strongly reminiscent of Adustochaete . Both genera include resupinate species with spinulose or smooth, grayish or brownish, easily crumbling, arid basidiomata and richly encrusted hyphae. Moreover, their hyphae and hymenial cells are sometimes brownish, evidently due to the color of the cytoplasm. The contents of these coloured cells clearly stain in CB (cyanophilous) in Adustochaete spp. while they normally stay unchanged or show only a weak cyanophilous reaction in Leiostroma . Another trait separating the two genera is the crystalline incrustation on hyphae. Species of both genera produce abundant, small, angular or sand-like (fine-grained) crystals; these crystals, however, mostly remain discrete in Adustochaete and often fuse together and produce continuous shields, especially on basal hyphae and apical branches of hyphidia, in Leiostroma . Furthermore, Leiostroma spp. have well-differentiated basidia-bearing hyphae which are as a rule wider than the surrounding subhymenial hyphae; no such differentiation was observed in the Adustochaete spp. studied by us.</p><p>Differences between Adustochaete and another similar-looking genus, Proterochaete, are more obvious. Proterochaete spp. possess tougher basidiomata than those of Adustochaete, which consist of densely arranged, partly glued hyphae. Along with angular crystals, hyphae and hymenial cells of many Proterochaete spp. also bear brownish, cyanophilous grains fusing in large amorphous bodies in mature and especially senescent basidiomata. See further remarks under Adustochaete hiemalis .</p></div>	https://treatment.plazi.org/id/B0D6C74F057B54819C6727677100FF9E	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
2B1EF7B379C4591896BD15512E2C4CAA.text	2B1EF7B379C4591896BD15512E2C4CAA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete rava R. L. M. Alvarenga & K. H. Larss.	<div><p>Adustochaete rava R. L. M. Alvarenga &amp; K. H. Larss., Botany 97: 442, 2019</p><p>Holotype.</p><p>Brazil • Rondônia: Porto Velho, São Francisco Farm, deciduous wood, 15 Mar 2012, Larsson 15526 * (URM 92997, isotype – H, studied) .</p><p>Description.</p><p>Basidiomata annual, effused, up to 5 cm in the longest dimension, waxy-arid, rather soft, 0.05–0.2 mm thick. Hymenial surface spinulose, grayish to gray or pale grayish-brown, in older parts with small dark-brown spots, spines rather regularly distributed, sharp-pointed, 75–200 × 35–40 μm, 7–8 per mm. Margin first arachnoid to fimbriate, adnate, then sharply delimited and somewhat elevated, white, up to 1 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or brownish, thin- to slightly thick-walled, interwoven or subparallel, loosely arranged, in older parts agglutinated, 1.5–4 μm in diam., subhymenial hyphae hyaline or rarely brownish, thin-walled or with a distinct wall, ascending or interwoven, rather densely arranged and partly agglutinated, 1.5–3 μm in diam., hyphae of hymenial spines hyaline or more often brownish, slightly thick-walled, ascending or interwoven, 1.5–3 μm in diam., occasionally cemented by brownish amorphous substance. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Cystidia abundant to rather rare, hyaline, thin- to slightly thick-walled, clavate or more or less clearly tapering, often sinuous, 21–52 × 4–8 μm. Hyphidia hyaline or brownish, thin- to slightly thick-walled, with hyphoid or narrowly clavate, occasionally branched stem, 20–40 × 2–5 μm, bearing several richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex; apical branches densely encrusted by small, densely arranged crystals. Basidia four-celled, ellipsoid-ovoid to nearly obconical, sessile, (9.5 –) 11–16 (– 16.5) × (7.2 –) 7.3–10.5 (– 11.2) μm (n = 30 / 2), thin-walled or with a distinct wall, exposed or embedded, occasionally with a reduced stalk-like base, up to 4 × 4 μm, sterigmata up to 18 × 3–4 μm. Basidiospores thin-walled, narrowly cylindrical to cylindrical, clearly curved, (10.1 –) 10.2–13.7 (– 14.2) × (3.7 –) 3.8–5.1 (– 5.2) μm (n = 60 / 2), L = 11.83–12.01, W = 4.13–4.55, Q = 2.62–2.91.</p><p>Remarks.</p><p>Adustochaete rava was described based on the single collection from Rondônia, Brazil (Alvarenga et al. 2019). Here we supplement its description and report it from Argentina. Morphologically, A. rava can be easily distinguished from other neotropical Adustochaete spp. due to brownish tints of its basidiomata, as well as narrow basidiospores. The species was illustrated in Alvarenga et al. (2019). Phylogenetically, A. rava is closely related to two other spinulose Adustochaete species from the neotropics, A. minuta and A. nivea (Figs 2, 13, 14).</p></div>	https://treatment.plazi.org/id/2B1EF7B379C4591896BD15512E2C4CAA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
4BA78139DC635873BCC88C1A04604FBF.text	4BA78139DC635873BCC88C1A04604FBF.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete scalena Spirin & Ryvarden 2026	<div><p>Adustochaete scalena Spirin &amp; Ryvarden sp. nov.</p><p>Fig. 15 F</p><p>Holotype.</p><p>Zimbabwe • Mashonaland East: Binga Swamp Forest, dry partly corticated angiosperm branch, 14 Jan 1989, Ryvarden 26006 * (O, isotype – H) .</p><p>Etymology.</p><p>Scalenus (Lat., adj.) – scalene, unequilateral; in reference to a variable spore shape.</p><p>Description.</p><p>Basidiomata annual, effused, up to 3 cm in the longest dimension, arid, rather soft, 0.1–0.2 mm thick. Hymenial surface smooth or indistinctly tuberculate, grayish-ochraceous to brownish-gray, sometimes irregularly cracking. Margin floccose, nearly white, adnate, up to 0.3 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, thin-walled or with a distinct wall, subparallel or interwoven, anastomosing, 2–5 μm in diam., subhymenial hyphae hyaline, thin-walled, predominantly interwoven, rather loosely arranged, 1.5–4 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Cystidia (gloeocystidia) rather rare, thin-walled, single, more or less clearly tapering, often somewhat swollen at the base, 43–63 × 7.5–11.5 μm, contents brownish to grayish-brown, CB +. Hyphidia hyaline or brownish to grayish-brown, thin-walled, single or in groups of 2–3, with subfusiform or hyphoid stem, 20–54 × 3.5–9 μm, bearing several richly branched apical outgrowths, 1–2 μm in diam. at the very apex; apical branches encrusted by small, densely arranged crystals. Basidia four-celled, narrowly obconical, sessile, (19 –) 23.5–30 (– 30.5) × (10.2 –) 11.2–14.2 (– 14.3) μm (n = 20 / 1), thin-walled, mostly exposed, occasionally with a reduced stalk-like base, up to 5 × 3 μm, sterigmata up to 45 × 4–5 μm. Basidiospores thin-walled, broadly cylindrical, slightly or moderately curved, or narrowly ellipsoid, (11.1 –) 11.2–15.8 (– 16.2) × (6.2 –) 6.3–9.1 (– 9.2) μm (n = 30 / 1), L = 13.80, W = 7.90, Q = 1.75.</p><p>Remarks.</p><p>Adustochaete scalena is described here based on a single collection from Zimbabwe. It differs from A. fumida, another smooth Adustochaete species from the same area, in having darker basidiomata, larger and more abundant cystidia, as well as longer basidia and wider basidiospores. The basidiospores of A. scalena are quite diverse in shape, varying from curved-cylindrical to nearly ellipsoid. Superficially, the basidiomata of A. scalena are reminiscent of senescent, withered individuals of Proterochaete furfurosa . Their differences are listed under the latter species.</p></div>	https://treatment.plazi.org/id/4BA78139DC635873BCC88C1A04604FBF	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
DB577AA417295482861592B3C91BE1DD.text	DB577AA417295482861592B3C91BE1DD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Adustochaete tribulata Spirin & Ryvarden 2026	<div><p>Adustochaete tribulata Spirin &amp; Ryvarden sp. nov.</p><p>Fig. 15 G</p><p>Holotype.</p><p>Uganda • Kabarole: Kibale National Park, Makere University Field Station, dead, partly corticated branches, 20 Apr 2002, Ryvarden 44803 * (O, isotype – H) .</p><p>Etymology.</p><p>Tribulatus (Lat., adj.) – sharpened.</p><p>Description.</p><p>Basidiomata annual, effused, gregarious, up to 2 cm in the longest dimension, arid, rather soft, 0.05–0.1 mm thick. Hymenial surface spinulose, cream-colored to grayish, spines rather regularly distributed, sharp-pointed, 60–200 × 40–50 μm, 8–10 per mm. Margin pruinose, white to cream-colored, adnate, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, slightly thick-walled, subparallel, tightly agglutinated, not encrusted, 2–4 μm in diam., subhymenial hyphae hyaline, thin- to slightly thick-walled, interwoven, rather loosely arranged, 2–3 μm in diam., occasionally inflated up to 5 μm in diam., hyphae of hymenial spines hyaline, slightly thick-walled, ascending, CB (+), some irregularly inflated, 1.5–3.5 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular or sand-like. Cystidia occasionally present, hyaline or grayish-brownish, thin- to slightly thick-walled, clavate to broadly clavate or somewhat tapering, sometimes sinuous, predominantly embedded, 15–30 × 6–12 μm. Hyphidia abundant, dominating in hymenial layer, hyaline, slightly or distinctly thick-walled, CB (+), originating from subtend subhymenial hyphae, frequently dichotomously branched, 1–1.5 μm in diam. at the very apex, richly encrusted by small, densely arranged crystals. Basidia four-celled, ellipsoid-ovoid to nearly obconical, sessile, (12.5 –) 13–17 (– 17.5) × (9.3 –) 9.7–12.1 (– 12.2) μm (n = 23 / 1), thin-walled or with a distinct wall, embedded or exposed, sterigmata up to 15 × 3–3.5 μm. Basidiospores thin-walled, narrowly cylindrical to cylindrical, clearly curved, (11.4 –) 12.1–17.0 (– 17.2) × (4.8 –) 5.0–5.8 (– 6.1) μm (n = 30 / 1), L = 14.85, W = 5.30, Q = 2.82.</p><p>Remarks.</p><p>Adustochaete tribulata is macroscopically similar to two other whitish Adustochaete species described above, viz. A. minuta and A. nivea . It differs from them in having firm, abundant, richly branched and encrusted hyphidia dominating in the hymenial layer. Adustochaete tribulata is the single spinulose Adustochaete species so far detected in Africa. It is currently known only from the type locality in Uganda.</p></div>	https://treatment.plazi.org/id/DB577AA417295482861592B3C91BE1DD	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
8D87440FC0675EB4943FE8015ABD5954.text	8D87440FC0675EB4943FE8015ABD5954.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Descidia repanda (Fr.) Spirin 2026	<div><p>Descidia repanda (Fr.) Spirin comb. nov.</p><p>Figs 15 H, 16 B</p><p>≡ Exidia repanda Fr., Systema Mycologicum 2: 225, 1822. Neotype (selected by Aoki and Tubaki 1986: 881). Sweden. Uppland: Lena, Ängeby, Rönningen, Betula sp., 11 Nov 1935, Bruun &amp; Lundell (Lundell &amp; Nannfeldt, Fungi Exsiccati Suecici # 266) (UPS F-010989, studied) .</p><p>= Exidia qinghaiensis S. R. Wang &amp; Thorn, Mycoscience 62: 213, 2021. Holotype. China. Qinghai: Menyuan, Xianmi, Betula sp., 19 Oct 2004, Xiaoqing (HMAS 156328 *) .</p><p>Description.</p><p>Basidiomata annual, first cushion-shaped, adpressed-orbicular or turbinate, up to 3 cm in diam., narrowly or broadly attached, later fusing together and forming compound cerebriform basidiomata, up to 20 cm in the longest dimension and 2 cm thick, gelatinous. Hymenial surface smooth to indistinctly or clearly folded, amber-yellow to reddish or reddish-brown, in dry condition normally darkening to dirty-brown, sometimes with a lilac hue. Abhymenial surface smooth, concolourous with hymenial surface. Margin free, concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin- to slightly thick-walled, interwoven or subparallel, spaced, anastomosing, 0.5–6.5 μm in diam., subhymenial hyphae hyaline or yellowish, thin- to slightly thick-walled, predominantly interwoven, 1–4 μm in diam., basidia-bearing hyphae 2–4 μm in diam. Hyphidia with a hyaline or yellowish, often slightly thick-walled, hyphoid stem, 2–5 μm in diam., and hyaline apical branches, 0.5–1.2 μm in diam., in mature basidiomata cemented by yellowish or reddish amorphous substance and forming a continuous layer up to 35 μm thick. Probasidia predominantly tapering, 9–20 × 4–6 μm. Basidia four-celled, ellipsoid-ovoid, (9 –) 9.5–16 (– 16.5) × (7.6 –) 7.8–9.7 (– 10.3) μm (n = 40 / 4), sterigmata up to 15 × 1.5–2 μm. Basidiospores narrowly cylindrical to allantoid, usually distinctly curved, (9.2 –) 10.1–15.1 (– 15.4) × (2.7 –) 2.8–4.1 (– 4.2) μm (n = 150 / 5), L = 11.87–13.11, W = 3.15–3.75, Q = 3.19–4.19.</p><p>Remarks.</p><p>Descidia repanda is widely distributed in the temperate and boreal areas of Eurasia. It occurs exclusively on dead, hanging or just fallen, corticated branches of Betula spp. No verified records of D. repanda from North America are known to us. Macroscopically, D. repanda is most similar to Exidia candida . Their differences are discussed under the latter species. This species was first introduced by Fries (1822) as Exidia repanda . No original specimens of E. repanda exist and the protologue implies that Fries’ species was originally a mixture of E. repanda in the present sense and E. candida . In particular, Alnus as a host tree and minute, papillose projections on the hymenial surface point to the latter species. Nevertheless, E. repanda was neotypified with a specimen growing on Betula (Aoki and Tubaki 1986) . We studied the neotype and concluded that it is conspecific with E. repanda as it was interpreted in North Europe by Neuhoff (1935), Raitviir (1970), Torkelsen (1972), and Hansen and Knudsen (1997). Specimens and sequences of E. repanda by Wu et al. (2020) belong to Exidia straminea instead (see below).</p></div>	https://treatment.plazi.org/id/8D87440FC0675EB4943FE8015ABD5954	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
721BFD3FAB4B5682905B34280079853F.text	721BFD3FAB4B5682905B34280079853F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Descidia Spirin 2026	<div><p>Descidia Spirin gen. nov.</p><p>Etymology.</p><p>From ‘descisco’ (Lat., verb) – to secede, to desert.</p><p>Description.</p><p>Basidiomata annual, gelatinous, resupinate, with elevated margin, or adpressed-orbicular, turbinate to nearly cerebriform, hyaline, white or ivory-yellowish to light orange-brown. Abhymenial surface smooth; hymenial surface almost smooth to indistinctly or clearly folded, spine-like projections absent. Crystals accidental. Hyphal structure monomitic; hyphae clamped, as a rule not encrusted. Cystidia absent. Hyphidia present, usually forming a continuous layer. Basidia four-celled, longitudinally septate, ellipsoid-ovoid. Basidiospores hyaline, thin-walled, cylindrical or allantoid, often distinctly curved. On dead wood of angiosperms.</p><p>Generic type.</p><p>Tremella thuretiana Lév.</p><p>The genus is introduced here to accommodate two Exidia s. lato species, E. repanda and E. thuretiana, which cluster together outside of the main Exidia clade (Figs 1, 2). These species differ from almost all genuine Exidia species in having a rather loose epihymenial layer which is composed of smooth (i. e. non-encrusted) apical branches of hyphidia. Moreover, E. repanda and E. thuretiana do not produce spine-like projections on the hymenial surface, which are characteristic of the great majority of Exidia s. str. species. See further remarks under Exidia . The exidioid representatives of Ulocolla (i. e. Exidia saccharina and related species) often lack these projections, too. However, the epihymenial layer in these species consists of variably thick-walled and often inflated, pigmented (brownish) hyphidia. Moreover, jelly-like species of Ulocolla occur exclusively on coniferous hosts while the two Descidia spp. are restricted to angiosperm wood.</p></div>	https://treatment.plazi.org/id/721BFD3FAB4B5682905B34280079853F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
47ECF90A050B535FB8049428734DAA86.text	47ECF90A050B535FB8049428734DAA86.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Descidia thuretiana (Lev.) Spirin 2026	<div><p>Descidia thuretiana (Lév.) Spirin comb. nov.</p><p>Figs 15 I, 16 C, 18</p><p>≡ Tremella thuretiana Lév., Annals des Sciences Naturelles, Botanique 3 (9): 127, 1848. Lectotype (selected here, MBT 10031428). France. Seine-et-Marne: Bussy-Saint-Martin, Rentilly, Carpinus betulus, [no collecting date], Léveillé (PC, studied) .</p><p>= Exidia thuretiana (Lév.) Fr., Hymenomycetes Europaei: 694, 1874.</p><p>= Heterochaete europaea Höhn., Annales Mycologici 1: 393, 1903. Holotype. Bosnia and Herzegovina. Central Bosnia: Jajce, Fagus sylvatica, 14 Apr 1901, Höhnel (FH 00304798, studied) .</p><p>= Sebacina plumbea Bres. &amp; Torrend, Brotéria, sér. Bot. 11: 87, 1913. Holotype. Portugal. [no locality and collecting date indicated], Torrend (S F 20661, studied) .</p><p>Description.</p><p>Basidiomata annual, at first cushion-shaped or adpressed-orbicular, up to 2 cm in diam., broadly attached, later partly or completely fusing together and forming compound effused basidiomata, up to 30 cm in the longest dimension and 1.5 cm thick, gelatinous. Hymenial surface smooth or covered by shallow folds, pure white to cream-coloured, sometimes with a bluish hue, in older basidiomata with brownish tints, especially at the middle, in dry condition darkening to grayish- or reddish-brown. Abhymenial surface smooth, concolorous with hymenial surface. Margin sharply delimited, often somewhat elevated and partly detaching, occasionally radially furrowed or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin-walled or with a distinct wall, interwoven, anastomosing, 0.5–5 μm in diam., subhymenial hyphae hyaline, thin-walled or with a distinct wall, ascending or interwoven, 0.5–3 μm in diam., basidia-bearing hyphae 2–6 μm in diam. Hyphidia with a hyaline, hyphoid or subfusiform stem, 1.5–9 μm in diam., and hyaline apical branches, 0.5–2 μm in diam., forming rather loose continuous layer up to 30 μm thick. Probasidia clavate or tapering, 15–30 × 5–9.5 μm. Basidia four-celled, embedded or exposed, ellipsoid-ovoid to almost obconical, more rarely subglobose, (16 –) 17–28 (– 29) × (9.9 –) 10.6–19.1 (– 19.2) μm (n = 60 / 6), occasionally with a distinct stalk-like base, up to 7 × 3.5 μm, sterigmata up to 70 × 2.5–3 μm. Basidiospores cylindrical to broadly cylindrical, distinctly curved, (11.8 –) 12.1–20.2 (– 20.9) × (5.1 –) 5.2–8.1 (– 8.2) μm (n = 264 / 9), L = 14.87–18.43, W = 5.79–7.03, Q = 2.26–2.88.</p><p>Remarks.</p><p>Pale basidiomata, often showing a strong tendency to effused growth, as well as large basidiospores make Descidia thuretiana easily recognizable. Microscopically, it is similar to two effused Exidia species, E. delita and E. plumbescens, described below. From them, D. thuretiana can be differentiated by its larger basidia and basidiospores. Moreover, the basidiome margin of D. thuretiana is always elevated and often (at least partly) detached from the substrate. In the two aforementioned Exidia spp., the margin is constantly adnate and gradually thinning. Descidia thuretiana is widely distributed in nemoral and hemiboreal zones of Europe. It occurs on a wide range of angiosperm trees and shrubs (and rarely also on thick grass stems) in both natural and human-induced habitats. Another member of Descidia, D. repanda, differs from D. thuretiana in having smaller basidia, as well as shorter and distinctly narrower basidiospores. The basidiomata of D. repanda are more distinctly colored, and it occurs exclusively on Betula branches, mostly in areas with a continental climate.</p><p>The species was first described by Léveillé (1848) as Tremella thuretiana . According to the protologue, the original collections of T. thuretiana were made from branches of Fagus sylvatica . We could not trace them in herbarium PC. Therefore, we select the only authentic specimen (with Léveillé’s own handwriting) collected in the type locality as a lectotype of T. thuretiana . This specimen is in relatively good condition, fertile, and is undoubtedly conspecific with other D. thuretiana collections studied by us. Due to its macroscopic variability, D. thuretiana was subsequently described at least twice, as Heterochaete europaea and Sebacina plumbea (see synonymy above). Both taxa refer to D. thuretiana in its effused condition.</p><p>Some authors have argued that Tremella albida is, in fact, the oldest available name for D. thuretiana (Brefeld 1888; Neuhoff 1936 a; Donk 1966). After studying the protologue of T. albida (Hudson 1778), as well as the species’ reintroduction in the sanctioning work (Fries 1822), we find it hard to believe that T. albida is conspecific with D. thuretiana . Hudson’s description is difficult to interpret unambiguously, and his reference to ‘ Echinus gelatinosus crystallinus ’ by Haller (1768) (currently Pseudohydnum gelatinosum) makes it even more difficult to understand. As for Fries’ redescription of T. albida, it is almost equally ambiguous, although some elements (undulate basidiomata, yellowish colouration) suggest that Fries most likely dealt with small, discoloured forms of Tremella mesenterica Retz. No authentic specimens of T. albida are extant, however, and our suggestion is merely hypothetical.</p></div>	https://treatment.plazi.org/id/47ECF90A050B535FB8049428734DAA86	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
2AE58E1CCB5553E38DB1E52D86582621.text	2AE58E1CCB5553E38DB1E52D86582621.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Eichleriella Bres.	<div><p>Eichleriella Bres., Annales Mycologici 1: 115, 1903</p><p>= Amphistereum Spirin &amp; Malysheva, Fungal Biology 121: 696, 2017. Generic type. Eichleriella schrenkii Burt.</p><p>Note.</p><p>For a description, see Malysheva and Spirin (2017).</p><p>Generic type</p><p>(lectotype). Eichleriella incarnata Bres. (selected by Burt 1915: 743).</p><p>In our earlier treatment of Eichleriella and related genera (Malysheva and Spirin 2017), the genus Amphistereum was introduced to encompass two stereoid, dimitic species, A. leveilleanum and A. schrenkii . In the ITS – LSU-based phylogeny, they clustered with Eichleriella s. str., although without statistical support, and so were placed in a separate genus. Our current data (Figs 1, 2) show that A. leveilleanum is part of a strongly supported Eichleriella clade. Amphistereum is therefore considered a later synonym of Eichleriella .</p></div>	https://treatment.plazi.org/id/2AE58E1CCB5553E38DB1E52D86582621	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
79A72E158B5F5D67B38225279669DD77.text	79A72E158B5F5D67B38225279669DD77.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Eichleriella macrochaeta (Bres. & Torrend) Spirin & Malysheva 2026	<div><p>Eichleriella macrochaeta (Bres. &amp; Torrend) Spirin &amp; Malysheva comb. nov.</p><p>≡ Heterochaete macrochaeta Bres. &amp; Torrend, Brotéria, sér. Bot. 11: 86, 1913. Holotype. Portugal. Lisbon: Sintra, Quercus suber, [no collection date indicated], Torrend 236 (S F 21050, studied) .</p><p>= Sebacina shearii Burt, Annals of the Missouri Botanical Garden 2: 758, 1915. Holotype. USA. District Columbia: Washington, Dept. of Agriculture Grounds, Berberis vulgaris, 25 Oct 1902, Shear 1238 (BPI 719719 – isotype, studied) .</p><p>= Eichleriella shearii (Burt) Spirin &amp; Malysheva, Fungal Biology 121: 708, 2017.</p><p>Note.</p><p>Bresadola and Torrend (Torrend 1913) introduced Heterochaete macrochaeta based on a single collection from Portugal. Wells (1961) suggested that H. macrochaeta could be conspecific with Sebacina strigosa Bourdot &amp; Galzin described from France (Bourdot and Galzin 1909). After studying type specimens of both species, we concluded that they belong to two different species. Heterochaete macrochaeta is definitely the same species as Eichleriella shearii (Burt) Spirin &amp; Malysheva which is widely distributed in America and also occurring in Europe (see Malysheva and Spirin 2017). Since H. macrochaeta predates H. shearii, a new combination in Eichleriella is proposed here. Our data confirm the presence of E. macrochaeta in the southern part of Africa. As for S. strigosa, it was made the generic type of Fibulosebacea by Wells and Raitviir (1987). Despite its high morphological similarity to some Exidiopsis s. lato species, our data suggest that S. strigosa does not belong to Auriculariaceae or even Auriculariales . Its proper taxonomic placement will be clarified on another occasion.</p></div>	https://treatment.plazi.org/id/79A72E158B5F5D67B38225279669DD77	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
B7EA698807505530958D8C6DAD3583DC.text	B7EA698807505530958D8C6DAD3583DC.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Elmericium spinosum Spirin & Viner 2026	<div><p>Elmericium spinosum Spirin &amp; Viner sp. nov.</p><p>Fig. 15 J</p><p>Holotype.</p><p>Cameroon • Campo Prov.: Akok Lowland Rainforest Reserve, corticated angiosperm branch on the ground, 2–15 Dec 1991, Ryvarden 30580 * (O, isotype – H) .</p><p>Etymology.</p><p>Spinosus (Lat., adj.) – spinose, bearing spines.</p><p>Description.</p><p>Basidiomata annual, effused, up to 10 cm in the longest dimension, opaque, gelatinous, 0.1–0.2 mm thick. Hymenial surface smooth or spinulose, gray to brownish-gray, spines irregularly distributed, sharp or blunt, up to 100 × 100 μm, 6–8 per mm. Margin gradually thinning, concolourous with hymenial surface, adnate, up to 1 mm wide.</p><p>Hyphal structure dimitic (skeletals present in subiculum only), hyphae clamped; subicular generative hyphae hyaline, slightly to distinctly thick-walled, CB (+) to CB +, subparallel, tightly agglutinated, 1.5–3.5 μm in diam., skeletal hyphae rather rare, hyaline, distinctly thick-walled, CB (+), 1–2 μm in diam., subhymenial hyphae hyaline, thin-walled or with a distinct wall, interwoven, rather densely arranged and partly agglutinated, 1–3 μm in diam., hyphae of hymenial spines hyaline, slightly or distinctly thick-walled, CB (+) to CB +, ascending or interwoven, 2–4.5 μm in diam. Crystals abundant in all parts of basidiomata, angular, often in large groups (up to 25 μm in widest dimension). Cystidia absent. Hyphidia hyaline, thin-walled, richly branched, 1.5–2 μm in diam. (apical branches), partly covering basidial cells. Basidia four-celled, ellipsoid-ovoid to broadly ellipsoid, sessile, (12 –) 13–15.5 (– 16) × (8.1 –) 8.2–11.2 (– 11.8) μm (n = 20 / 1), with a distinct wall or slightly thick-walled, exposed, often glued in groups of up to four, occasionally with a reduced stalk-like base, up to 5 × 5 μm, sterigmata up to 11 × 3–3.5 μm. Basidiospores thin-walled, narrowly cylindrical to cylindrical, clearly curved, (8.6 –) 9.1–11.3 (– 12.2) × (3.7 –) 3.9–4.7 (– 4.8) μm (n = 30 / 1), L = 10.32, W = 4.19, Q = 2.47.</p><p>Remarks.</p><p>Despite their phylogenetic affinity, E. spinosum and E. alabastrinum (the generic type of Elmericium) show quite significant morphological differences. Macroscopically, E. spinosum can be differentiated from E. alabastrinum by its spinulose hymenophore (vs. completely smooth in the latter species). The most striking anatomical feature of E. spinosum is the presence of subicular skeletal hyphae strongly reminiscent of narrow, occasionally branched, solid skeletals of the poroid Aporpium hexagonoides A. David &amp; Jaq. from the Elmerina clade. In turn, basidiomata of E. alabastrinum are completely monomitic. Moreover, E. alabastrinum possesses cystidia, and its basidia and basidiospores are clearly larger than those of E. spinosum . Basidia of E. alabastrinum have a long and thick basal stalk. This basal basidial segment, if present, is strongly reduced in E. spinosum .</p></div>	https://treatment.plazi.org/id/B7EA698807505530958D8C6DAD3583DC	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
11D617F470915C85885BD5BA3E19BE23.text	11D617F470915C85885BD5BA3E19BE23.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Elmericium Spirin & Malysheva	<div><p>Elmericium Spirin &amp; Malysheva, MycoKeys 120: 348, 2025</p><p>Note.</p><p>For a description, see Spirin et al. (2025).</p><p>Generic type.</p><p>Elmericium alabastrinum Spirin &amp; Malysheva.</p><p>This genus was recently introduced as monotypic, with the East Asian E. alabastrinum as the sole species (Spirin et al. 2025). Here we expand it with the newly described E. spinosum from Africa (see Suppl. material 5).</p></div>	https://treatment.plazi.org/id/11D617F470915C85885BD5BA3E19BE23	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
E5F049CE585E561B8EF727966D5687BB.text	E5F049CE585E561B8EF727966D5687BB.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia benieri Pat.	<div><p>Exidia benieri Pat., Journal de Botanique 8: 221, 1894</p><p>Fig. 36 H</p><p>Holotype.</p><p>Tunisia • El Fedja, Laurus nobilis, Oct 1893, Bénier (FH 00784211, studied) .</p><p>Exidia benieri was described from Tunisia (Patouillard 1894). No modern records of this species are known to us. Morphologically, it is a member of the E. pithya complex. Due to its broadly cylindrical basidiospores, E. benieri is strongly reminiscent of E. inornata (see description above). The spores are, however, shorter in E. benieri than in E. inornata, (9.1 –) 10.5–12.8 (– 12.9) × (4.8 –) 4.9–6.5 (– 6.6) μm (n = 30 / 1), L = 11.64, W = 5.53, Q = 2.12. Moreover, it occasionally possesses blunt or spine-like projections on the hymenial surface, similar to those of E. pithya and most other Exidia spp. which are lacking in E. inornata . We therefore prefer to keep E. benieri and E. inornata separate, awaiting newly collected and sequenced material from North Africa.</p></div>	https://treatment.plazi.org/id/E5F049CE585E561B8EF727966D5687BB	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
5B6B20FB3DF159CE98D36951030F03D2.text	5B6B20FB3DF159CE98D36951030F03D2.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia candida Lloyd	<div><p>Exidia candida Lloyd, Mycological Writings 5: 620, 1916</p><p>Fig. 16 D, E</p><p>= Exidia villosa Neuhoff, Pilze Mitteleuropas 2: 22, 1935. Neotype (designated by Spirin et al. 2018: 5). Norway. Oslo: Bygdøy, Dronningberget, Tilia cordata, 3 May 2016, Spirin 10012 * (O, studied) .</p><p>= Exidia cartilaginea S. Lundell &amp; Neuhoff, Pilze Mitteleuropas 2: 19, 1935. Lectotype (selected by Spirin et al. 2018: 7). Sweden. Uppland: Bondkyrka, Vårdsätra, Betula sp., 18 Oct 1932, Lundell (Fungi Exsiccati Suecici # 263) (UPS F-010986, studied) .</p><p>Lectotype</p><p>(selected by Spirin et al. 2018: 5). USA • Washington: Clallam Co., Sequim, [no collecting date], Grant (BPI 701884, studied) (Fig. 16 D, E).</p><p>Description.</p><p>Basidiomata annual, at first cushion-shaped or adpressed-orbicular, up to 5 cm in diam., broadly attached, later partly fusing together and forming compound cerebriform basidiomata, up to 20 cm in the longest dimension and 2 cm thick, gelatinous. Hymenial surface uneven or folded, occasionally bearing regularly arranged spine-like projections up to 0.3 mm long, white to cream-coloured or pale ochraceous-brownish, sometimes darker, reddish-brown, in dry condition darkening to brown or brownish-black. Abhymenial surface smooth, concolourous with hymenial surface. Margin sharply delimited, elevated, concolourous with hymenial surface, or adnate, fimbriate, whitish and gradually thinning.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin-walled or with a distinct wall, interwoven, anastomosing, 0.5–5 μm in diam., subhymenial hyphae hyaline or yellowish, thin-walled or with a distinct wall, predominantly interwoven, 1.5–4 μm in diam., basidia-bearing hyphae 2–4 μm in diam., often showing a zigzag-like branching pattern. Hyphidia with a hyaline or yellowish, hyphoid or narrowly clavate stem, 2.5–6 μm in diam., and hyaline or yellowish apical branches, 1–2 μm in diam., forming a continuous layer up to 40 μm thick. Probasidia clavate or tapering, 10–22 × 4–7 μm. Basidia four-celled, predominantly embedded, ellipsoid-ovoid, occasionally distinctly tapering to the base, (12 –) 12.5–18 (– 21) × (7.8 –) 7.9–11.3 (– 11.4) μm (n = 30 / 3), sometimes obliquely septate, sterigmata up to 30 × 2–2.5 μm. Basidiospores narrowly to broadly cylindrical, distinctly curved, (8.7 –) 8.9–15.2 (– 15.6) × (3.1 –) 3.2–5.2 (– 5.3) μm (n = 240 / 8), L = 10.23–12.40, W = 3.97–4.55, Q = 2.35–3.12.</p><p>Remarks.</p><p>Exidia candida was described from the US North-West (Lloyd 1916) and recently reinstated by Spirin et al. (2018). Here we redescribe it based on a larger set of specimens from the northern hemisphere. The species is macroscopically very variable. Its darker-colored forms with a well-developed epihymenial membrane were assigned to var. cartilaginea (Spirin et al. 2018) . This variety occurs mainly in the northern areas of Eurasia. The southern, “ typical ” variety (= E. villosa) is lighter-coloured, softer and it often (but not always!) bears sharp outgrowths on the hymenial surface. This feature, as well as its shorter and wider basidiospores help to separate E. candida from the superficially similar D. repanda . Phylogenetically, E. candida is more closely related to the effused Exidia spp. ( E. delita, E. japonica, E. plumbescens) than to other members of the genus with reflexed basidiomata (Figs 1, 2).</p></div>	https://treatment.plazi.org/id/5B6B20FB3DF159CE98D36951030F03D2	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
11FF59A7D2D354C8882A0EE06A2AB55A.text	11FF59A7D2D354C8882A0EE06A2AB55A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia ciliata (Moller) Spirin 2026	<div><p>Exidia ciliata (Möller) Spirin comb. nov.</p><p>≡ Exidiopsis ciliata Möller, Botanische Mittheilungen aus den Tropen 8: 91, 1895. Lectotype (selected by Alvarenga et al. 2019: 449). Brazil, Santa Catarina, Blumenau, on bark, 1891, Möller 10 (91) (HBG) .</p><p>= Tremellochaete ciliata (Möller) Spirin &amp; Alvarenga, Botany 97: 449, 2019.</p><p>For a description and further synonymy, see Alvarenga et al. (2019).</p></div>	https://treatment.plazi.org/id/11FF59A7D2D354C8882A0EE06A2AB55A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
0A984B4F719552E981A378F8EE2D6D79.text	0A984B4F719552E981A378F8EE2D6D79.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia cinnamomescens Raitv.	<div><p>Exidia cinnamomescens Raitv., Tartu Riikliku Ülikooli Toimetised 136: 208, 1963</p><p>= Myxarium cinnamomescens (Raitviir) Raitviir, Plants and Animals of the Far East: 113, 1971.</p><p>Holotype.</p><p>Russia • Komi Rep.: Syktyvdinsky Dist., Graddor, Populus tremula (fallen log), 8 Aug 1957, Põldmaa (TAAM 5995 *, studied) .</p><p>Note.</p><p>This species was first described as a member of Exidia (Raitviir 1963) and later combined in Myxarium (Raitviir 1971) . It was accepted as M. cinnamomescens in our recent publications (Spirin et al. 2018, 2019, 2025). The species name was associated with a sister species of M. populinum (P. Karst.) Spirin &amp; Malysheva, inhabiting various angiosperm hosts in temperate and boreal forests of Eurasia. The two species have been separated almost exclusively based on their spore size (mainly the spore width). The basidiospore dimensions from the type specimen of E. cinnamomescens fall within the same range with other specimens so labelled, (9.3 –) 10.2–13.4 (– 13.7) × (4.0 –) 4.1–5.3 (– 5.8) μm (n = 30 / 1), L = 11.88, W = 4.75, Q = 2.52. Those latter specimens were used by us for DNA studies. However, the ITS sequence newly obtained from the type specimen of E. cinnamomescens shows that it is conspecific with M. populinum . It means that the species named as M. cinnamomescens in our previous publications needs a new species epithet.</p><p>There are four names for the European exidioid Myxarium spp. which had remained unaddressed in our earlier studies, i. e. Tremella gemmata Lév., Exidia corrugativa Bref., Tremella ilicis Boud., and Exidia alboglobosa Lloyd. The type material of T. gemmata (in PC, studied) belongs to M. hyalinum as typified and redescribed in Spirin et al. (2018). As far as we know, no extant material exists for E. corrugativa and T. ilicis . In our opinion, their original illustrations (published by Brefeld 1888; Boudier 1911, correspondingly) again represent M. hyalinum . Finally, the type of E. alboglobosa (BPI 701610, studied) most likely belongs to a sister species of M. nucleatum Wallr., devoid of mineral inclusions (see comments in Spirin et al. 2019: 6–7). This necessitates introducing M. cinnamomescens sensu auct. as a new species:</p></div>	https://treatment.plazi.org/id/0A984B4F719552E981A378F8EE2D6D79	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
18E0648FCE6D5AE7B64AC7FC9855AAAD.text	18E0648FCE6D5AE7B64AC7FC9855AAAD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia crenata (Schwein.) Fr.	<div><p>Exidia crenata (Schwein.) Fr., Systema Mycologicum 2: 226, 1822</p><p>Fig. 19 A</p><p>≡ Tremella crenata Schwein., Schriften der Naturforschenden Gesellschaft zu Leipzig 1: 115, 1822. Holotype. USA. North Carolina, [no collecting date indicated], Schweinitz 1141 (PH) .</p><p>= Tremella corrugata Schwein., Transactions of the American Mycological Society 4: 185, 1832. Holotype. USA. Pennsylvania: Bethlehem, [no collecting date indicated], Schweinitz 1113 (PH 00077946, studied) .</p><p>Description.</p><p>Basidiomata annual, cupulate-orbicular, up to 2 cm in diam., narrowly attached, later partly fusing together but remaining separable, up to 0.5 cm thick, gelatinous. Hymenial surface uneven or folded, rarely bearing scattered granular projections up to 0.1 mm long, at first ochraceous- to reddish-brown, later dark brown, in dry condition darkening to nearly black. Abhymenial surface rough, covered by tightly arranged dots, reddish-brown or dark brown. Margin free, concolourous with hymenial surface, first entire, even or indistinctly lobate, in older basidiomata usually distinctly incised (crenate).</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or yellowish, occasionally encrusted, thin- to slightly thick-walled, interwoven, anastomosing, 1–5 μm in diam., subhymenial hyphae hyaline or yellowish, occasionally encrusted, thin- to slightly thick-walled, predominantly ascending, 1.5–4 μm in diam., basidia-bearing hyphae with a distinct wall, 2–3 μm in diam. Hyphidia with a hyaline or yellowish-brownish, often encrusted, hyphoid or more rarely subfusiform stem, 2–12 μm in diam., and hyaline or yellowish apical branches, 0.8–2 μm in diam., covered by yellowish-brownish gelatinous matrix and forming a continuous layer up to 25 μm thick. Probasidia distinctly tapering or more rarely clavate, 11–15 × 5–7 μm. Basidia four-celled, ellipsoid-ovoid, (10 –) 10.5–15 (– 15.5) × (7.2 –) 7.3–10.6 (– 11.4) μm (n = 30 / 2), sterigmata up to 20 × 1.5–2 μm. Basidiospores cylindrical to allantoid, slightly or distinctly curved, (9.3 –) 10.2–14.2 (– 14.3) × (3.1 –) 3.2–4.6 (– 4.8) μm (n = 90 / 3), L = 11.30–11.73, W = 3.71–3.90, Q = 2.92–3.20.</p><p>Remarks.</p><p>This species was first described as Tremella crenata (Schweinitz 1822) and the same year moved to Exidia (Fries 1822) . Coker (1920) studied the type material of both T. crenata and T. corrugata and placed them as synonyms of the European E. recisa (as E. gelatinosa). Since then, E. crenata was almost totally forgotten. Recently, Wu et al. (2020) reinstated E. crenata as a species on its own and provided a color photo, as well as a brief comparison of it with the newly described E. yadongensis from East Asia. We affirm their observations. Exidia crenata is phylogenetically closely related to E. yadongensis, and they belong to the E. recisa complex (Fig. 9). They can hardly be separated from each other under the microscope. Macroscopically, the scalloped (crenate) margin of mature E. crenata individuals is quite characteristic; in E. yadongensis, the margin remains more or less entire. Exidia crenata occurs exclusively in the eastern part of North America where it inhabits dead branches of Quercus spp. In turn, E. yadongensis is distributed in East Asia on various deciduous hosts.</p></div>	https://treatment.plazi.org/id/18E0648FCE6D5AE7B64AC7FC9855AAAD	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
9F38A79DE5755655ACED4153828124C7.text	9F38A79DE5755655ACED4153828124C7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia delita Spirin & Schoutteten 2026	<div><p>Exidia delita Spirin &amp; Schoutteten sp. nov.</p><p>Figs 16 F, 19 B</p><p>Holotype.</p><p>France • Aveyron: Combret, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=2.71597&amp;materialsCitation.latitude=43.86348" title="Search Plazi for locations around (long 2.71597/lat 43.86348)">Bétirac</a>, 43.86348; 2.71597, Populus nigra (fallen decorticated log), 6 Nov 2024, Spirin 17810 * (H, isotype – PC) .</p><p>Etymology.</p><p>Delitus (Lat., part. pf.) – plastered, spread.</p><p>Description.</p><p>Basidiomata annual, effused, up to 7 cm in the widest dimension, gelatinous, opalescent, up to 0.3 mm thick. Hymenial surface indistinctly tuberculate and whitish in fresh condition, smooth and dirty-grayish after drying; mineral inclusions occasionally present, white, mostly small and visible only under lens. Margin rather clearly delimited, adnate, gradually thinning, concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, with variably thickened, gelatinized walls, mostly subparallel, hardly distinguishable, 2–3.5 μm in diam., subhymenial hyphae hyaline or yellowish, thin-walled, easily collapsing, predominantly interwoven, 1.5–3 μm in diam., occasionally covered by small, densely arranged, acicular crystals, basidia-bearing hyphae thin-walled, 2.5–6 μm in diam., occasionally showing a zigzag-like branching pattern. Crystals single, angular, scattered or forming large agglomerations, up to 20 μm in widest dimension. Hyphidia richly branched, with a poorly differentiated, hyphoid stem, 2–4 μm in diam., and hyaline apical branches, 1–1.5 μm in diam., occasionally forming a continuous, rather loose layer up to 20 μm thick. Probasidia ellipsoid-ovoid to broadly clavate, 12–17 × 6–11 μm. Basidia four-celled, often obliquely septate, ellipsoid-ovoid to almost obconical, sessile, (14 –) 14.5–20 (– 21) × (9.7 –) 10.1–12.4 (– 12.9) μm (n = 20 / 1), thin-walled, exposed or rarely embedded, occasionally with a tapering, stalk-like base, up to 12 × 2–7 μm, sterigmata up to 35 × 2.5–3.5 μm. Basidiospores thin-walled, cylindrical, more rarely broadly cylindrical, often distinctly curved, (11.3 –) 11.9–17.2 (– 17.5) × (4.5 –) 4.7–6.4 (– 6.5) μm (n = 62 / 2), L = 13.44–14.77, W = 5.22–5.87, Q = 2.53–2.58.</p><p>Remarks.</p><p>Exidia delita is a look-alike of E. plumbescens, reintroduced below. It differs from the latter species due to its thinner basidiomata, smaller basidia and hyphidia with poorly differentiated, slenderer stems. The basidiospores of E. delita are on average shorter than in most specimens of E. plumbescens studied by us; however, their dimensions overlap. Although these species look very much the same and are congeneric, they are not closely related phylogenetically (Figs 1, 2). Exidia delita is so far known only from two localities, in France and the Netherlands.</p></div>	https://treatment.plazi.org/id/9F38A79DE5755655ACED4153828124C7	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
CEF68008F562525391D86AF5525DF2B4.text	CEF68008F562525391D86AF5525DF2B4.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia Fr.	<div><p>Exidia Fr., Systema Mycologicum 2: 220, 1822</p><p>= Tremellochaete Raitv., Eesti NSV Teaduste Akadeemia Toimetised 13: 29, 1964. Generic type. Exidia japonica Lloyd.</p><p>Description.</p><p>Basidiomata annual, gelatinous, adpressed-orbicular, turbinate or cerebriform, more rarely resupinate and then with adnate, gradually thinning margin, reddish-brown to almost black, more rarely lighter-coloured. Abhymenial surface smooth, dotted, papillose or hirsute; hymenial surface smooth to indistinctly or clearly folded, spine-like projections present in most species. Crystals usually abundant; dark-colored granular incrustation as a rule present on hyphidia and hyphae (apparently lacking in five pale-coloured species). Hyphal structure monomitic; hyphae clamped, in many species encrusted. Cystidia present only in two resupinate species. Hyphidia present, often forming a continuous layer (epihymenial membrane). Basidia four-celled, longitudinally septate, ellipsoid-ovoid or broadly clavate. Basidiospores hyaline, thin-walled, broadly cylindrical to allantoid, usually distinctly curved. On dead wood of angiosperms, more rarely on conifers.</p><p>Generic type.</p><p>Tremella glandulosa Bull.</p><p>Here we reintroduce Exidia for most species previously ascribed to this genus, at least those distributed in Europe. Two other genera encompassing Exidia - like fungi are Descidia and Ulocolla . From them, Exidia s. str. can be distinguished due to two quite distinctive features. First, the majority of Exidia spp. treated below possess spine-like or (in some subtropical / tropical species formerly treated under Tremellochaete) wart-like projections on the hymenial surface. However, these seem to be constantly lacking in a few species of Exidia s. str. Some individuals of the normally papillose species can be devoid of them, too. Additionally, Ulocolla saccharina may sometimes develop clearly visible and rather regularly arranged hymenial projections. In these cases, the genuine Exidia species can be separated from the other exidioid taxa by the permanent presence of the characteristic granular encrustations on hyphidia and, in many cases, also on subhymenial and context hyphae (Figs 21, 22). These discrete deposits are as a rule coloured reddish, brownish or nearly black, and their presence causes the overall basidiome colouration. The incrustation of this type is clearly different from the amorphous yellowish or brownish substance cementing an epihymenial layer in mature basidiomata of Descidia repanda and the exidioid Ulocolla spp. The only two exceptions known to us are Exidia candida and E. semiorbis . In these species, no signs of granular encrustation on hyphidia or hyphae have been detected. Moreover, the epihymenial membrane in E. candida var. candida (= E. villosa) is very loose and it is eventually absent in E. semiorbis . These deviating features make it difficult to differentiate these two species from similar Descidia spp. However, most specimens of E. candida and all known specimens of E. semiorbis bear spine-like projections on their hymenial surface. The basidiospores of E. candida are cylindrical to broadly cylindrical and shorter than in Descidia spp. These two traits help in differentiating E. candida from the superficially similar D. repanda and D. thuretiana . The basidiospores of E. semiorbis are very similar to those of D. repanda . However, mature basidiomata of E. semiorbis are orbicular-cupulate and have a warted abhymenial surface, while they are turbinate or pulvinate and smooth on the outside in D. repanda .</p><p>The inclusion of four completely resupinate, smooth species in Exidia, i. e. Sebacina plumbescens (= Exidiopsis succinea) and the newly described Exidia delita, E. repleta, and E. saturata, poses another problem – namely, it obfuscates the limits of Exidia vs. the redefined Exidiopsis ( E. effusa and E. perflua), Proterochaete ( P. abstrusa), Tegmenticium ( T. peritrichum) and Ulocolla ( U. grisea). The four effused Exidia species can be differentiated from the representatives of the aforementioned genera by their thicker, clearly gelatinous basidiomata and, as a rule, larger basidia. In E. delita and E. plumbescens, the basidiomata usually produce numerous embedded mineral grains easily detectable under magnification. These inclusions are very rare or completely lacking in the similar-looking species of Exidiopsis, Proterochaete, Tegmenticium, or Ulocolla . In turn, E. repleta and E. saturata can be differentiated from the representatives of the four mentioned genera in having thicker epihymenial layer and distinctly inflated hyphae.</p><p>The identity of the generic type, E. glandulosa, is still a subject of ongoing controversy. We address this issue in remarks to E. glandulosa, E. pithya and E. truncata . In total, 26 Exidia species are described or commented on below and several insufficiently known taxa belonging to the redefined Exidia are addressed in the corresponding section of the paper.</p></div>	https://treatment.plazi.org/id/CEF68008F562525391D86AF5525DF2B4	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
AC0ADB04B0D95CE49B7E70203F5BFE79.text	AC0ADB04B0D95CE49B7E70203F5BFE79.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia friesiana P. Karst.	<div><p>Exidia friesiana P. Karst. in von Thümen, Mycotheca Universalis 12: 1111, 1878</p><p>Figs 19 C, 20 A</p><p>Lectotype</p><p>(selected here, MBT 10031432). Finland • Etelä-Häme: Hämeenlinna, Tammela, Mustiala, Picea abies, March. 1878 Karsten (H, studied) .</p><p>Description.</p><p>Basidiomata annual, at first button-shaped or adpressed-orbicular, up to 5 cm in diam., broadly attached, later fusing together but remaining partly separable and forming compound effused basidiomata, up to 20 cm in the longest dimension, up to 0.5 cm thick, gelatinous. Hymenial surface variably folded, very rarely bearing scattered granular projections up to 0.1 mm long, brownish- to bluish-black, in dry condition completely black, shining. Abhymenial surface smooth, concolourous with hymenial surface. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline to grayish, thin-walled or with a distinct wall, predominantly subparallel, anastomosing, 1–6 μm in diam., subhymenial hyphae hyaline to grayish, thin-walled or with a distinct wall, ascending, 1–4 μm in diam., basidia-bearing hyphae 2–5 μm in diam. Hyphidia with a slightly thick-walled, grayish or brownish, hyphoid or nodulose stem, 2–11 (16) μm in diam., and grayish or brownish apical branches, 1–2 μm in diam., forming rather loose continuous layer up to 60 μm thick. Probasidia clavate or tapering, 12–17 × 6–8 μm. Basidia thin- to slightly thick-walled, four-celled, ellipsoid-ovoid, (12.5 –) 13.5–19 (– 20) × (9.1 –) 10.0–14.4 (– 15.2) μm (n = 54 / 4), sterigmata up to 20 × 2–2.5 μm. Basidiospores narrowly to broadly cylindrical, distinctly curved, (10.2 –) 10.7–18.8 (– 19.2) × (4.0 –) 4.1–6.5 (– 6.6) μm (n = 171 / 6), L = 12.61–15.89, W = 4.39–5.43, Q = 2.41–3.16.</p><p>Remarks.</p><p>Exidia friesiana is widely distributed in the northern hemisphere and occurs exclusively on recently fallen, often still corticated wood remnants of Abies and Picea spp. In the Mediterranean, it was also found on Pinus halepensis . Before the present study, E. friesiana was treated under the misapplied name E. pithya (see remarks on the latter species). Still, the two species are closely related (Figs 9, 10) and morphologically quite similar. Macroscopically, E. friesiana can be separated from E. pithya by its consistent lack of spike-like hymenial projections, which are typically present in the latter species. Anatomically, E. friesiana is easily recognizable even if sterile because of its regularly ascending subhymenial hyphae. In E. pithya, subhymenial hyphae are arranged in a much more random manner, predominantly ascending in one part of the basidiome and mostly interwoven in another. It seems that the hyphal arrangement follows the hymenophore configuration, being nearly smooth or faintly radially plicate in E. friesiana and strongly and irregularly folded in mature individuals of E. pithya . Additionally, the basidiospores of E. friesiana are wider and normally longer than in E. pithya; however, specimens of both species are often sterile or contain only a few turgid spores. See further notes under E. pithya .</p></div>	https://treatment.plazi.org/id/AC0ADB04B0D95CE49B7E70203F5BFE79	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
5F5475085E3D56959EE8720A787CE986.text	5F5475085E3D56959EE8720A787CE986.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia fuliginea Mont. 1850	<div><p>Exidia fuliginea Mont., Historia física y política de Chile, Botánica 7: 393, 1850</p><p>Holotype.</p><p>Chile • O’Higgins: Rancagua, rotten log, [no collecting date], Bertero 701 (Montagne’s herbarium # 1104) (PC, studied) .</p><p>Exidia fuliginea was described from Chile (Gay 1850) and is so far known only from the type specimen. Macroscopic traits, i. e. dark-brown resupinate basidiomata with a somewhat lobed margin and spinose hymenial surface (1–2 projections per mm), as well as encrusted, blackish hyphidia and cylindrical, curved basidiospores, (9.8 –) 10.0–14.2 (– 16.8) × (3.6 –) 3.9–5.2 (– 5.3) μm (n = 20 / 1), L = 12.21, W = 4.46, Q = 2.76, point to Exidia as an appropriate genus for this species. However, sequenced material of E. fuliginosa is necessary to infer its phylogenetic relationships with other Exidia spp.</p></div>	https://treatment.plazi.org/id/5F5475085E3D56959EE8720A787CE986	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
80B1606A17C055CDA5E9A86E27BFBD62.text	80B1606A17C055CDA5E9A86E27BFBD62.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia glandulosa (Bull.) Fr.	<div><p>Exidia glandulosa (Bull.) Fr., Systema Mycologicum 2: 224, 1822</p><p>Figs 19 D, 20 B, 21</p><p>≡ Tremella glandulosa Bull., Herbier de la France 9: pl. 420, fig. 1, 1789. Lectotype (iconotype) (selected here, MBT 10031433). Fig. 1, pl. 420 in Bulliard, Herbier de la France 9, 1789. Epitype (designated here, MBT 10031434). Sweden. Västergötland: Askim, Årekärr, Alnus glutinosa, 15 Mar 1999, E. Larsson 3-99 * (GB-0150310, studied) .</p><p>= Exidia strigosa (P. Karst.) P. Karst., Bidrag till Kännedom av Finlands Natur och Folk 48: 451, 1889. Holotype. Finland. Varsinais-Suomi: Turku, Ruissalo, Corylus avellana, 2 Jun 1869, Karsten 2141 (H 6061342, studied) .</p><p>= Exidia grambergii Neuhoff, Zeitschrift für Pilzkunde 5: 187, 1926.</p><p>Description.</p><p>Basidiomata annual, at first button-shaped or adpressed-orbicular, up to 5 cm in diam., narrowly attached and occasionally with a reduced stalk-like base up to 2 cm long, later turbinate or nearly cupulate, up to 10 cm in diam., sometimes in large groups and partly fusing together, up to 3–4 cm thick, gelatinous. Hymenial surface uneven or variably folded, covered by rather regularly arranged spike-like black projections up to 0.25 mm long, dark gray to brownish-gray, later brownish-black, in dry condition completely black. Abhymenial surface felty or strigose, covered by densely arranged blackish hairs up to 0.2 mm long, grayish-brown to nearly black. Margin free, concolourous with hymenial surface, entire, even or lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or grayish, thin- to distinctly thick-walled, predominantly interwoven, anastomosing, 1–7 μm in diam., subhymenial hyphae hyaline to grayish, thin-walled or with a distinct wall, predominantly ascending, 1–3 μm in diam., basidia-bearing hyphae 2–4 μm in diam. Hyphidia with a hyaline or grayish-brownish hyphoid stem, 2–9 μm in diam., and hyaline or grayish-brownish apical branches, 0.5–1 μm in diam., forming a continuous layer up to 100 μm thick. Probasidia clavate to broadly clavate, more rarely tapering, 12–21 × 5–10 μm. Basidia four-celled, ellipsoid-ovoid, thin- or occasionally thick-walled (wall up to 1–1.5 μm thick), (14 –) 14.5–24 (– 25) × (9.6 –) 9.7–13.7 (– 13.8) μm (n = 85 / 8), sterigmata up to 50 × 1.5–2.5 μm. Basidiospores narrowly cylindrical to cylindrical, moderately or strongly curved, (10.3 –) 11.0–17.9 (– 19.1) × (3.9 –) 4.0–6.4 (– 6.8) μm (n = 330 / 10), L = 13.53–15.87, W = 4.56–5.47, Q = 2.48–3.31.</p><p>Remarks.</p><p>As redefined here, E. glandulosa is morphologically and phylogenetically the closest to E. truncata . They both produce adpressed-orbicular or turbinate, nearly black basidiomata with a distinctly spinulose hymenial surface. These species also share similar ecological preferences, being collected and sometimes occurring side by side in the same habitats (nemoral or hemiboreal forests with Quercus robur), as a rule on hanging or just fallen branches. Exidia glandulosa differs from E. truncata in having a hairy abhymenial surface (scabrose or minutely punctate in E. truncata) and on average shorter basidiospores.</p><p>Up to the present moment, the identity of E. glandulosa has remained controversial. Neuhoff (1936 b) made the first attempt to sort out names of the dark-colored Exidia species in Europe. He coined the name E. glandulosa (based on Buillard’s T. glandulosa) and applied it to the most common black Exidia species with prostrate basidiomata and smooth abhymenial surface. At the same time, he named a similar species with orbicular or turbinate basidiomata and uneven upper surface E. truncata . Neuhoff (ibid.) referred to descriptions of E. glandulosa and E. truncata in Systema Mycologicum (Fries 1822) and stated that they leave no doubt about Fries’ concept of these species. Moreover, he mentioned that the authentic specimens of E. glandulosa in Fries’ herbarium in Uppsala corroborate his concept. Neuhoff’s viewpoint on the identity of E. glandulosa and E. truncata was accepted by most subsequent authors (Pilát 1957; Raitviir 1970; Torkelsen 1972; Wojewoda 1981; Hansen and Knudsen 1997). In recent DNA studies, E. glandulosa and E. truncata sensu Neuhoff were adopted by Weiß and Oberwinkler (2001), Wu et al. (2020) and Ye et al. (2020).</p><p>Donk (1966) proposed an alternative interpretation of the two species. He pointed to the ambiguity of Fries’ descriptions of E. glandulosa and stated that some elements of the text in Systema Mycologicum definitely refer to E. truncata . Therefore, it is highly likely that Fries himself could not distinguish between the two species. The only certain element in his introduction of E. glandulosa (Fries 1822) is a reference to Bulliard’s illustration of Tremella glandulosa (Bulliard 1789) . It clearly depicts E. truncata as interpreted by Neuhoff (1936 b), and, in Donk’s opinion, also as understood by Fries himself. As a consequence, Donk (1966) synonymized E. truncata with E. glandulosa and formally introduced a new name, E. plana, for E. glandulosa sensu Neuhoff. Roberts (2009) accepted this synonymy but proposed another name, E. nigricans, for E. plana .</p><p>We agree with Donk’s opinion that Fries’ concept of E. glandulosa was quite obscure and that the single clear element in his description is the link to Bulliard’s illustration of T. glandulosa . We could not trace any specimens in UPS collected or received by Fries prior to the publication of his description of E. glandulosa in 1822. Hence, it is uncertain which specimens in Fries’ herbarium in Uppsala Neuhoff referred to. However, there are two specimens with Fries’ handwritings in Lund (herbarium LD) which he studied before publishing Systema Mycologicum. One specimen labelled as Tremella arborea Huds. (LD 1473064) is identical with E. glandulosa in the sense of Donk and Roberts and the second one (‘ Tremella spiculata Pers. ’, LD 1473124) belongs to E. nigricans . Both T. arborea and T. spiculata were listed by Fries (1822) as synonyms of E. glandulosa, and this confirms Donk’s assertion that E. glandulosa sensu Fries was a mixture of (at least) two species.</p><p>Exidia glandulosa has never been typified. The existence of the two authentic specimens by Fries, as well as his reference to Bulliard’s illustration of T. glandulosa, confront us with a difficult choice, because either of the specimens or the illustration can be used for typification. One option would be to select the specimen LD 1473124 as a lectotype of T. glandulosa and thus support Neuhoff’s view on the identity of this species. This would allow for the retention of E. glandulosa as it has been accepted in recent DNA studies. However, this selection would be in the explicit conflict with the original species concept presented by Bulliard (1789), as well as, to some degree, with Fries’ opinion on its identity. From his description and synonymy in Systema, we still can conclude that his E. glandulosa mainly referred to a species with a strigose abhymenial surface. We therefore support Donk’s conclusions on the identity of E. glandulosa but exclude E. truncata from its synonyms. The latter species is redescribed and discussed below. We designate Bulliard’s original illustration of T. glandulosa as its lectotype and supplement it with an epitype collected on alder (the only host tree mentioned by Bulliard in the protologue of T. glandulosa).</p><p>No type material is extant for E. grambergii . The species description (Neuhoff 1926) certainly refers to E. glandulosa as redefined here. We place E. grambergii in the synonyms of E. glandulosa .</p></div>	https://treatment.plazi.org/id/80B1606A17C055CDA5E9A86E27BFBD62	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
6E45EB4649405BB89512A0C84DB571A0.text	6E45EB4649405BB89512A0C84DB571A0.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia impressa (Pers.) Fr.	<div><p>Exidia impressa (Pers.) Fr., Systema Mycologicum 2: 226, 1822</p><p>Figs 19 E, 20 C, 22</p><p>≡ Tremella impressa Pers., Mycologia Europaea 1: 102, 1822. Neotype (selected here, MBT 10031435). France. Aveyron: Millau, Le Monna, Laburnum sp. (dead hanging branch), 23 Feb 2025, Spirin 18143 * (H) .</p><p>Description.</p><p>Basidiomata annual, cupulate-orbicular, up to 3 cm in diam., narrowly attached, up to 0.5 cm thick, gelatinous. Hymenial surface even or indistinctly folded, rarely bearing spine-like outgrowths up to 0.3 mm long, dark reddish-brown to brownish-black, in dry condition completely black. Abhymenial surface rough, covered by tightly arranged dots, brownish-black. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or yellowish, with a variably thickened, gelatinized wall, interwoven, anastomosing, occasionally encrusted, 1.5–7 μm in diam., sometimes inflated and then reaching up to 15 μm in diam., subhymenial hyphae hyaline or yellowish, thin-walled or with a distinct wall, predominantly ascending, 1.5–3 μm in diam., basidia-bearing hyphae thin-walled or with a distinct wall, 2–5 μm in diam., often short-celled. Hyphidia of two types: a) hymenial hyphidia, with a hyaline, narrowly clavate or nearly hyphoid stem, 3–5 μm in diam., and predominantly hyaline, usually rather short, dendroid or coralloid apical branches, 1–2 μm in diam.; b) deeply rooted hyphidia, with a hyaline or yellowish-brownish, often encrusted hyphoid stem, 3–8 μm in diam., and yellowish or brownish, usually rather long apical branches, 1–1.5 μm in diam., embedded in yellowish-brownish gelatinous matrix and forming a continuous layer up to 100 μm thick. Probasidia ellipsoid-ovoid, moderately tapering, or clavate, 10–17 × 3–7 μm. Basidia four-celled, narrowly ellipsoid-ovoid or broadly clavate, often obliquely septate, (13.5 –) 15–20 (– 21) × (5.1 –) 5.4–7.3 (– 7.4) μm (n = 20 / 1), sterigmata up to 50 × 1–2 μm. Basidiospores cylindrical to allantoid, slightly or distinctly curved, (8.8 –) 9.0–12.7 (– 13.1) × (3.0 –) 3.1–4.1 (– 4.2) μm (n = 30 / 1), L = 11.01, W = 3.52, Q = 3.16.</p><p>Remarks.</p><p>This species was described by Persoon (1822) as Tremella impressa . The protologue referred to another, provisional name, T. rufescens Ehrenb. Fries (1822) sanctioned T. impressa and moved it to Exidia although he had never studied it and simply repeated Persoon’s description. Since then, the identity of E. impressa has remained obscure. Bourdot and Galzin (1927) accepted it as a good species. However, their description seemingly refers to another species, E. straminea (see below). Neuhoff (1936 a) placed E. impressa in the synonyms of E. truncata (= E. glandulosa in the present study), and this synonymy was later accepted by Donk (1966).</p><p>In our opinion, Neuhoff’s species concept cannot be accepted because it contradicts some important elements mentioned in the protologue of T. impressa . First, Persoon (1822: 102) stated that his species becomes dark reddish-brown in dry condition (“ sicca … rufo fusca fit ”). Further, he specified that it is completely smooth after being rehydrated, and its margin is faintly plicate (“ humectata tota laevis … marginem parum plicata ”, ibid.). All these features clearly rule out E. glandulosa and E. truncata: neither of them show reddish tints, nor is the surface of their basidiomata smooth. Moreover, the basidiome edge of E. glandulosa is clearly folded and sometimes lobate. In E. truncata, as redescribed below, it remains entire and more or less even. The type material of E. impressa is not extant, and we therefore designate a recent, sequenced collection from France as a neotype of T. impressa . In all important aspects, it agrees with the descriptions of Persoon and Fries.</p><p>Morphologically, E. impressa is strongly reminiscent of species in the E. recisa complex. Due to its dark, opaque basidiomata, it can be easily separated from two other similar species in Europe, E. recisa and E. straminea . These two species have lighter-colored, semitranslucent basidiomata when fresh. Some individuals of E. impressa possess distinct, sharp projections on the hymenial surface. In contrast, the hymenial surface is completely smooth or only indistinctly warted in E. recisa and E. straminea . However, the presence of these outgrowths is inconsistent. In a collection of E. impressa containing multiple basidiomata, some of them may be completely devoid of the hymenial projections. Moreover, hyphidia of E. impressa are of two types – of subhymenial and tramal origin, and they are more or less clearly differentiated from each other. In E. recisa and especially in E. straminea, all kinds of transitions can be found between hymenial and deeply rooted hyphidia. In Asia, E. impressa can be confused with E. yadongensis and E. zelleri . All three species have dark, cupulate-orbicular basidiomata and similar host preferences, and they may occur in the same habitats. Exidia zelleri can be distinguished from E. impressa and E. yadongensis via its large basidiospores and (if sterile) much bigger basidia. Differences between E. impressa and E. yadongensis are discussed under the latter species.</p><p>We studied and sequenced three collections of E. impressa . They are morphologically very uniform but their ITS sequences show 5–6 bp difference from each other. All these positions are in the ITS 2 region. We preliminarily accept them as a sign of the infraspecific geographic variation. A much denser sampling from different parts of temperate Eurasia is necessary to prove otherwise.</p></div>	https://treatment.plazi.org/id/6E45EB4649405BB89512A0C84DB571A0	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
74193FDE0917586CBE2488E91EB2F2A8.text	74193FDE0917586CBE2488E91EB2F2A8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia inornata Cazenave & G. Gruhn	<div><p>Exidia inornata Cazenave &amp; G. Gruhn, Bulletin de la Société Mycologique de France 140: 219, 2024</p><p>Fig. 19 F</p><p>Holotype.</p><p>France • Hautes-Pyrénées: Séméac, Bois de Labarthe, Quercus sp., 26 Feb 2023, Cazenave (LIP GG-240916-002 *, isotype – H, studied) .</p><p>Description.</p><p>Basidiomata annual, button-shaped or adpressed-orbicular, up to 4 cm in diam., broadly attached, often in groups and partly fusing together, up to 1.5 cm thick, gelatinous. Hymenial surface variably folded, occasionally minutely warted, dark brownish-gray to brownish-black, in dry condition completely black. Abhymenial surface smooth, concolourous with hymenial surface. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or very pale grayish, thin- to slightly thick-walled, interwoven, anastomosing, occasionally encrusted, 1–6 μm in diam., subhymenial hyphae hyaline or grayish-brown, thin- to slightly thick-walled, ascending or interwoven, 1.5–4 μm in diam., some hyphae short-celled and inflated, up to 6–7 μm in diam., basidia-bearing hyphae thin- to slightly thick-walled, 2–5 μm in diam., occasionally irregularly inflated and then up to 6–8 μm in diam. Hyphidia with a grayish or brownish, hyphoid or nodulose stem, 2–9 μm in diam., and hyaline or brownish-gray apical branches, 1–2 μm in diam., forming a continuous layer up to 25 μm thick. Probasidia broadly clavate, more rarely tapering, 14–22 × 7.5–10.5 μm. Basidia four-celled, ellipsoid-ovoid to subglobose, (14 –) 14.5–19.5 (– 20) × (10.2 –) 10.3–13.5 (– 13.9) μm (n = 20 / 1), sterigmata up to 20 × 2.5–3 μm. Basidiospores cylindrical to broadly cylindrical, slightly or distinctly curved, (10.0 –) 10.1–15.8 (– 16.2) × (4.5 –) 4.8–6.2 (– 6.3) μm (n = 30 / 1), L = 13.15, W = 5.47, Q = 2.41.</p><p>Remarks.</p><p>Exidia inornata was recently described as a sister species of E. nigricans (= E. pithya in the present study) (Gruhn et al. 2024). Morphologically, it differs from the latter species due to the lack of projections on the hymenial surface and in having wider basidiospores. This species is so far known only from the southern part of France. Collections of E. friesiana from deciduous hosts mentioned by Bourdot and Galzin (1927) may actually belong to E. inornata instead. See also notes on E. benieri under insufficiently known species.</p></div>	https://treatment.plazi.org/id/74193FDE0917586CBE2488E91EB2F2A8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
678F2BF795D6526FAA68FF691015BE10.text	678F2BF795D6526FAA68FF691015BE10.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia japonica Lloyd	<div><p>Exidia japonica Lloyd, Mycological Writings 5: 599, 1916</p><p>= Tremellochaete japonica (Lloyd) Raitv., Eesti NSV Teaduste Akadeemia Toimetised 13: 30, 1964.</p><p>Exidia japonica is the generic type of Tremellochaete (Raitviir 1964; Malysheva and Spirin 2017). According to our phylogenetic analyses (Figs 1, 2), Tremellochaete must be treated as a part of the redefined Exidia . Thus, the original binomial is the correct name for this species.</p><p>Holotype.</p><p>Japan. Sendai, 3 Nov 1915, Yasuda 356 (TNS 203268, studied) .</p></div>	https://treatment.plazi.org/id/678F2BF795D6526FAA68FF691015BE10	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
D7F92FECD83E59638DF91DD16338F168.text	D7F92FECD83E59638DF91DD16338F168.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia novozealandica Lloyd	<div><p>Exidia novozealandica Lloyd, Mycological Writings 7 (75): 1356, 1925</p><p>Note.</p><p>In the protologue, Lloyd (1925) compared E. novozealandica with E. japonica and differentiated it from the latter species by its rougher, black hymenial projections. Cooper (2023) combined E. novozealandica in Tremellochaete although no justification was provided for this recombination. The identity of E. novozealandica deserves further study. See also the notes on E. tenax below.</p></div>	https://treatment.plazi.org/id/D7F92FECD83E59638DF91DD16338F168	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
B80B37C83F715AA1ADB9F4EF99E00BF6.text	B80B37C83F715AA1ADB9F4EF99E00BF6.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia pithya Fr.	<div><p>Exidia pithya Fr., Systema Mycologicum 2: 226, 1822</p><p>Figs 19 G, 19 H, 20 E, 20 F</p><p>= Tremella nigricans With., A Botanical Arrangement of All the Vegetables, Naturally Growing in Great Britain 2: 732, 1776.</p><p>= Exidia nigricans (With.) P. Roberts, Mycotaxon 109: 220, 2009.</p><p>= Exidia plana Donk, Persoonia 4: 228, 1966.</p><p>Neotype</p><p>(designated here, MBT 10031436). Sweden • Bohuslän: Hönö, Ersdalsvägen, Pinus sylvestris (fallen corticated log), 12 Aug 2024 Spirin 17359 * (GB) (Figs 19 G, 19 H, 20 E, 20 F) .</p><p>Description.</p><p>Basidiomata annual, at first cushion- or button-shaped, then adpressed-orbicular or more rarely nearly cerebriform, up to 5 cm in diam., broadly attached, in large groups, finally often fusing together and reaching 30 cm in the longest dimension, up to 1.5 cm thick, gelatinous. Hymenial surface uneven or variably folded, as a rule covered by rather regularly arranged spike-like black projections up to 0.2 mm long, at first gray to brownish-gray, later brownish-black, in older basidiomata sometimes fading to yellowish-brown, in dry condition completely black. Abhymenial surface smooth or near so, concolourous with or slightly paler than hymenial surface. Margin free, concolourous with hymenial surface, entire, even or lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline to grayish, occasionally encrusted by brownish deposits, thin- to slightly thick-walled, interwoven or subparallel, anastomosing, 0.5–6 μm in diam., subhymenial hyphae hyaline to grayish or brownish, thin-walled or with a distinct wall, ascending or interwoven, 1–3.5 μm in diam., occasionally irregularly inflated (up to 7.5 μm in diam.), basidia-bearing hyphae 2–5.5 μm in diam. Hyphidia with a brownish, occasionally irregularly inflated hyphoid stem, 2–10.5 μm in diam., and hyaline or brownish apical branches, 0.5–1 μm in diam., forming a continuous layer up to 50 μm thick. Probasidia bullet-shaped or broadly clavate, 10.5–23 × 4–10 μm. Basidia four-celled, ellipsoid-ovoid, (10 –) 11.5–20.5 (– 21.5) × (7.9 –) 8.1–11.8 (– 12.1) μm (n = 160 / 14), sterigmata up to 25 × 1–2.5 μm. Basidiospores narrowly to broadly cylindrical, more rarely allantoid, slightly or moderately curved, (8.1 –) 8.3–16.7 (– 19.7) × (3.1 –) 3.2–5.2 (– 5.3) μm (n = 560 / 19), L = 9.55–14.43, W = 3.59–4.61, Q = 2.49–3.49.</p><p>Remarks.</p><p>As redefined here, E. pithya is morphologically most similar to E. friesiana . Both species produce black or nearly black, adpressed-orbicular basidiomata with smooth abhymenial surface, soon fusing together and making up compound, irregularly shaped fructifications. The main macroscopic differences between the two species are a more distinctly folded hymenial surface of E. pithya compared to E. friesiana and the presence of sharp or blunt hymenial projections in the first species. Microscopically, E. pithya differs from E. friesiana in having more irregularly arranged subhymenial hyphae (often partly ascending and partly interwoven in the same fruitbody) and narrower and as a rule shorter basidiospores. Additionally, E. pithya occurs on both angiosperms and conifers, while E. friesiana is restricted to freshly fallen logs and branches of Abies and Picea spp. (as well as Pinus in the Mediterranean).</p><p>Up to now, E. pithya was believed to be a conifer-dwelling species which was differentiated from the similar E. glandulosa sensu Neuhoff (= E. nigricans after Roberts 2009) by its host preference. The latter species was described as growing exclusively on deciduous trees (Raitviir 1970; Hansen and Knudsen 1997). However, some authors noted that the so-called E. glandulosa can also be found on conifers (Neuhoff 1936 a; Pilát 1957; Torkelsen 1972; Wojewoda 1981), and that its only reliable trait versus E. pithya is the presence of hymenial outgrowths. This concept, as well as the application of the name E. pithya to the species without these projections came from Neuhoff (1936 a). In our opinion, this viewpoint cannot be maintained because it explicitly contradicts Fries’ description of E. pithya . In his sanctioning treatment, Fries (1822: 226) added the following remark to E. pithya: “ Ad truncos et ramos emortuos pineos, etiam mihi minute papillifera ”. The reference to minutely papillose hymenophore clearly excludes E. pithya in the sense of Neuhoff (= E. friesiana in the present study). Moreover, no verified records of the latter species on Pinus in temperate or boreal Europe are known to us. On the contrary, E. glandulosa sensu Neuhoff (= E. nigricans) occurs in the south-western part of Sweden on both angiosperms and conifers, including pine. We therefore designate one of the sequenced Swedish specimens collected on Pinus as a neotype of E. pithya . Tremella nigricans (= E. nigricans) is an older name for the species reinstated here as E. pithya . However, it has never been sanctioned. Thence, E. pithya has a priority over T. nigricans .</p><p>Exidia pithya is widely distributed in the northern hemisphere. Its differences from E. friesiana are listed above. However, the boundaries between the two species need further examination. The specimen Burdsall 12029, morphologically matching Exidia pithya and the only North American sample sequenced for more than one marker, shows a conflicting genetic pattern. Its ITS sequence is identical to the European E. pithya whereas its TEF 1 is the same as in E. friesiana . When two unlinked markers fully correspond to organisms from two different species, this usually indicates a very recent introgression event. Other processes, such as incomplete lineage sorting, are less likely – if these markers had been inherited from the ancestral population prior to the species split, enough time should have passed for at least some sequence divergence to accumulate. Denser sampling from North America and additional unlinked markers, ideally supported by mating tests, are needed to clarify this issue.</p><p>Another widely distributed species similar to E. pithya is E. spiculata . Like E. friesiana, it is totally devoid of the hymenial projections which are characteristic of E. pithya . However, in some collections of E. pithya they can be very sparse or completely lacking, although the number of these deviating specimens is relatively low. See further remarks under E. spiculata .</p></div>	https://treatment.plazi.org/id/B80B37C83F715AA1ADB9F4EF99E00BF6	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
3342BF438EC054E6B4A45B2FCCF320AD.text	3342BF438EC054E6B4A45B2FCCF320AD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia plumbescens (Burt) Spirin 2026	<div><p>Exidia plumbescens (Burt) Spirin comb. nov.</p><p>Figs 19 I, 20 D</p><p>≡ Sebacina plumbescens Burt, Annals of the Missouri Botanical Garden 3: 241, 1916 (nomen novum for S. plumbea Burt).</p><p>= Sebacina plumbea Burt, Annals of the Missouri Botanical Garden 2: 765, 1915 (nom. illeg., non S. plumbea Bres. &amp; Torrend). Holotype. USA. Washington: Klickitat Co., Bingen, Populus trichocarpa (fallen decorticated log), 18 Nov 1902, Suksdorf 862 (H – isotype, studied) .</p><p>= Sebacina burtii Trotter, Sylloge Fungorum 23: 573, 1925.</p><p>= Exidiopsis plumbescens (Burt) K. Wells, Lloydia 20: 53, 1957.</p><p>= Exidiopsis succinea K. Wells &amp; Raitv., Transactions of the British Mycological Society 89: 341, 1987. Holotype. Russia. Krasnoyarsk Reg.: Yenisseysk Dist., Yartsevo, Salix fragilis, 10 Aug 1958, Parmasto (TAAM 7008 *, studied) .</p><p>Description.</p><p>Basidiomata annual, effused, up to 10 cm in the widest dimension, gelatinous, opalescent, 0.5–1.5 mm thick. Hymenial surface smooth or indistinctly tuberculate, grayish to pale ochraceous in fresh condition, sometimes with reddish hues, corneous and amber-yellow to reddish-brown in herbarium; mineral inclusions abundant, white, first small and visible only under lens, in senescent basidiomata prominent and easily detectable. Margin rather clearly delimited, adnate, gradually thinning, concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, thin-walled or with variably thickened, gelatinized walls, tightly interwoven or subparallel, anastomosing, 1.5–4 μm in diam., subhymenial hyphae hyaline, thin-walled, predominantly ascending, tightly arranged, 1.5–3.5 μm in diam., occasionally inflated up to 6 μm in diam., basidia-bearing hyphae well-differentiated, 3–5 μm in diam., occasionally showing a zigzag-like branching pattern. Crystals present as large, rosette-like agglomerations, up to 25 μm in diam. Hyphidia richly branched, with a hyphoid or subfusiform stem, 15–35 × 5–7.5 μm, and hyaline apical branches, 1–1.5 μm in diam., partly covering basidia. Probasidia broadly clavate to subglobose, 10–18 × 6–10.5 μm. Basidia four-celled, ellipsoid-ovoid, more rarely subglobose, sessile, occasionally slightly tapering to the base, (14 –) 15–22 (– 23) × (10.0 –) 10.3–17.4 (– 18.0) μm (n = 70 / 7), thin- or slightly thick-walled, exposed or embedded, in older hymenium often surrounded by gelatinous substance, sterigmata up to 35 × 2.5–3 μm. Basidiospores thin-walled, narrowly to broadly cylindrical, often distinctly curved, (11.7 –) 12.1–19.4 (– 20.2) × (4.3 –) 4.5–7.8 (– 8.0) μm (n = 240 / 8), L = 14.11–16.17, W = 5.19–6.62, Q = 2.21–3.13.</p><p>Remarks.</p><p>This species was first described as Sebacina plumbea based on a single specimen from the US North-West (Burt 1915). Burt’s name turned out to be a younger homonym of S. plumbea described by Bresadola and Torrend two years earlier (see above, under synonyms of D. thuretiana). Consequently, it was validated by Burt (1916) as S. plumbescens . Trotter (Saccardo and Trotter 1925) also reintroduced S. plumbea under a new name, Sebacina burtii . However, it must be rejected as a homotypic synonym of S. plumbescens . This species was accepted by Wells (1957) as a member of Exidiopsis and combined therein. A few years later, Wells (1961) included E. plumbescens in his broadly interpreted E. grisea and then resurrected it as a good species again (Wells and Wong 1985). We studied type material of both S. plumbescens and Exidiopsis succinea described from Siberia (Wells and Raitviir 1987) and concluded that they are conspecific. DNA data place S. plumbescens in the redefined Exidia (Figs 1, 2).</p><p>Exidia plumbescens is widely distributed in the northern hemisphere although it is not common. In boreal forests, it occurs on dead branches and stems of Salix spp., more rarely on Populus spp. In more southern areas, it may inhabit other angiosperm trees ( Fagus and Ulmus). Wells and Wong (1985) gave a long list of substrates for Exidiopsis plumbescens from the North American Pacific coast. It is, however, not clear to us whether all these records refer to Exidia plumbescens sensu typi.</p><p>Exidia plumbescens is one of four entirely effused Exidia s. str. species dealt with in this paper. Of them, E. delita, differs from E. plumbescens in having thinner basidiomata, narrower hyphidia and on average smaller basidia and basidiospores (see above). Two other European species, E. repleta and E. saturata, differ from E. plumbescens in having thicker basidiomata covered by easily removable, whitish-grayish deposit. Both mentioned species possess a distinct epihymenial layer and they have cystidia. Moreover, hyphae of E. plumbescens are more or less evenly outlined while they are often clearly inflated in E. repleta and E. saturata .</p><p>Exidia plumbescens can also be confused with effused forms of Descidia thuretiana . The easiest way to distinguish between them is to check the basidiome margin: it is always adnate, gradually thinning in E. plumbescens and elevated, often partly detaching from the substrate in D. thuretiana . Spirin et al. (2025) showed that earlier records of Exidiopsis livescens from North Europe belong to Exidiopsis succinea ( Exidia plumbescens here). Previous reports and descriptions of Exidiopsis griseobrunnea from Norway (Torkelsen 1972; Hansen and Knudsen 1997) also refer to E. plumbescens .</p></div>	https://treatment.plazi.org/id/3342BF438EC054E6B4A45B2FCCF320AD	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
B2EB423968905E55800050FA3178F3A8.text	B2EB423968905E55800050FA3178F3A8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia punctata L. Wang & C. L. Zhao	<div><p>Exidia punctata L. Wang &amp; C. L. Zhao, Phytotaxa 689: 33, 2025</p><p>Note.</p><p>Phylogenetic data place E. punctata, recently described from China, in the genus Adustochaete (Figs 13, 14). The original description, although very sparse, points to this genus as well (Jiang et al. 2025). However, E. punctata cannot be combined in Adustochaete, due to the existence of another Adustochaete punctata described a year before (Dong et al. 2024). Therefore, a new name is needed. We are, however, unwilling to introduce it without studying authentic material of E. punctata . The environmental sequence GU 054135 in GenBank belongs to E. punctata or its close relative (Fig. 14).</p></div>	https://treatment.plazi.org/id/B2EB423968905E55800050FA3178F3A8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
E8826507A4EB50748D1FE57D4AB847B7.text	E8826507A4EB50748D1FE57D4AB847B7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia purpureocinerea MacOwan	<div><p>Exidia purpureocinerea MacOwan, Grevillea 10 (55): 106, 1882</p><p>Holotype.</p><p>South Africa. Eastern Cape: Somerset East, Boschberg, [no collecting date], MacOwan (K (M), isotype – S F 20629, studied) .</p><p>The type material of E. purpureocinerea is nearly sterile and badly infected, and only two turgid basidiospores were found, measuring 8.2–9.7 × 3.4–3.8 μm. These spore measurements, combined with the rather light-colored basidiomata and the presence of obtuse, regularly arranged (3–4 per mm, up to 70 × 60 μm) projections indicate that E. purpureocinerea is a member of the E. japonica complex. Morphologically, it is very similar to or probably even conspecific with Tremellochaete atlantica R. L. M. Alvarenga. The latter species was originally described from Brazil (Phookamsak et al. 2019) and later reported from the southern part of China (Tohtirjap et al. 2023). However, we refrain from synonymizing these species awaiting sequenced material of E. purpureocinerea from South Africa. Exidia tanzanica is another Tremellochaete - like species from Africa (see description above). It differs from E. purpureocinerea in having darker basidiomata with more densely arranged hymenial projections, as well larger basidia and basidiospores.</p></div>	https://treatment.plazi.org/id/E8826507A4EB50748D1FE57D4AB847B7	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
284045812D8E5024941E0753E4EDBC18.text	284045812D8E5024941E0753E4EDBC18.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia recisa (Ditm.) Fr.	<div><p>Exidia recisa (Ditm.) Fr., Systema Mycologicum 2: 223, 1822</p><p>Figs 20 G, 23 A, 23 B</p><p>≡ Tremella recisa Ditm. in Sturm, Deutschlands Flora, Abt. 3, 1 (1): 27, 1817. Lectotype (iconotype) (selected here, MBT 10031437). Table 13 ( Tremella recisa) in Sturm, Deutschlands Flora, Abtheilung 3, 1 (1), 1817. Epitype (selected here, MBT 10031438). Finland. Etelä-Häme: Muurame, Niittyaho, Salix fragilis, 18 Mar 2017, Laaka-Lindberg 1-180317 * (H) .</p><p>= Exidia brunneola P. Karst., Bidrag till Kännedom av Finlands Natur och Folk 48: 450, 1889. Holotype. Finland. Etelä-Häme: Tammela, Mustiala, Populus nigra, 2 Mar 1870, Karsten 2138 (H 6049699, studied) .</p><p>Description.</p><p>Basidiomata annual, cupulate-orbicular, up to 3 cm in diam., rarely up to 5 cm in diam., narrowly attached, later partly fusing together but remaining separable, up to 1 cm thick, gelatinous. Hymenial surface even or variably folded, rarely bearing scattered granular projections up to 0.1 mm long, at first ochraceous- to reddish-brown, later dark brown, in dry condition darkening to nearly black. Abhymenial surface rough, covered by tightly arranged dots, reddish-brown or dark brown. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate, in older basidiomata sometimes indistinctly incised.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or yellowish-brownish, occasionally encrusted, thin- to slightly thick-walled, interwoven or subparallel, anastomosing, 1–6.5 μm in diam., subhymenial hyphae hyaline or yellowish-brownish, occasionally encrusted, thin- to slightly thick-walled, predominantly interwoven, 1–4 μm in diam., basidia-bearing hyphae with a distinct wall, 1.5–4 μm in diam. Hyphidia with a hyaline or brownish, often encrusted, hyphoid or nodulose stem, 2–12 μm in diam., and hyaline apical branches, 0.5–1.2 μm in diam., covered by yellowish-brown gelatinous matrix and forming a continuous layer up to 80 μm thick. Probasidia distinctly tapering or more rarely clavate, 10.5–25 × 5–9 μm. Basidia four-celled, ellipsoid-ovoid, often somewhat tapering to the base, sometimes obliquely septate, (12 –) 12.5–18 (– 19) × (6.2 –) 6.3–10.8 (– 11.5) μm (n = 60 / 6), sterigmata up to 35 × 1.5–2.5 μm. Basidiospores narrowly cylindrical to allantoid, distinctly curved, (9.2 –) 11.0–17.9 (– 19.2) × (2.8 –) 2.9–4.2 (– 4.3) μm (n = 240 / 8), L = 13.14–15.82, W = 3.15–3.83, Q = 3.15–4.48.</p><p>Remarks.</p><p>Exidia recisa is a common species in Europe. It mostly inhabits branches and thin stems of Salix spp. in various habitats but rarely occurs on hanging or just fallen twigs of other angiosperms ( Padus, Populus, Tilia, and Ulmus). The occurrence on Salix and on average longer basidiospores help to differentiate it from other European representatives of the E. recisa complex, i. e. E. impressa, E. straminea and E. umbrinella . However, specimens of E. recisa from the other host trees, especially those with shorter basidiospores, can be easily mistaken for E. impressa and E. straminea . In these cases, additional morphological characters (basidiome color, the presence of hymenial projections, as well as the shape of hyphidia) should be used for species identification. The eastern distribution limits of E. recisa are unknown. According to our data, the easternmost record of this species is in Khakassia, Central Siberia.</p><p>The species was first introduced by Ditmar (in Sturm 1817) as Tremella recisa and then moved to Exidia by Fries (1822). No authentic material of T. recisa is known to us. We therefore select the original illustration by Ditmar as the lectotype of this species and supplement it with a newly selected and sequenced epitype. Exidia brunneola was described from Finland based on a single collection from a poplar tree (Karsten 1889) which is not native to the country. However, its morphological traits do not separate it from other E. recisa specimens studied by us. We therefore relegate E. brunneola to the synonyms of E. recisa .</p></div>	https://treatment.plazi.org/id/284045812D8E5024941E0753E4EDBC18	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
74A3210F46015E899FC62A16E17CB340.text	74A3210F46015E899FC62A16E17CB340.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia reflexa F. Wu, L. F. Fan & S. Y. Ye	<div><p>Exidia reflexa F. Wu, L. F. Fan &amp; S. Y. Ye, Mycological Progress 19: 862, 2020</p><p>Holotype.</p><p>China • Jilin: Antu, Changbai, Tilia sp., 21 Sep 2019, Dai 20861 * (BJFC) .</p><p>Exidia reflexa is a member of the E. pithya complex (Figs 10, 11) distributed in temperate East Asia. It differs from other similar species of the E. pithya group in having the smallest basidiospores, 9–10 × 2–2.5 μm. Exidia reflexa was described from China (Ye et al. 2020) and is reported here from Far East Russia.</p></div>	https://treatment.plazi.org/id/74A3210F46015E899FC62A16E17CB340	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
1937603E4290500EB2AD1FCC82A486F8.text	1937603E4290500EB2AD1FCC82A486F8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia repleta Spirin & Viner 2026	<div><p>Exidia repleta Spirin &amp; Viner sp. nov.</p><p>Fig. 23 B</p><p>Holotype.</p><p>France • Var: Toulon, Mont Faron, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=5.9248&amp;materialsCitation.latitude=43.1437" title="Search Plazi for locations around (long 5.9248/lat 43.1437)">Plateau des Jésuits</a>, 43.1437; 5.9248, Quercus coccifera (dead hanging branch), 23 Jan 2026, Spirin 18748 * (H, isotype – PC) .</p><p>Etymology.</p><p>Repletus (Lat., adj.) – replete, filled; in reference to water-soaked basidiomata.</p><p>Description.</p><p>Basidiomata annual, effused, first appearing as small, gregarious frustulae, 0.5–1.5 mm in diam., then partly fusing together (but remaining discernible) and forming compound basidiomata, up to 3 cm in the longest dimension, gelatinous, opaque, 0.1–0.2 mm thick. Hymenial surface smooth or indistinctly tuberculate, entirely covered by grayish-white to watery-gray, easily removable pruina, occasionally with grayish-brown flecks, in older individuals partly disappearing and showing a darker, brownish inner layer. Margin clearly delimited, adnate, gradually thinning, concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, slightly thick-walled, mostly interwoven, anastomosing, 1.5–5 μm in diam., occasionally strongly inflated (up to 8–10 μm in diam.), subhymenial hyphae hyaline or yellowish-brownish, thin- to slightly thick-walled, predominantly ascending, 1.5–5 μm in diam., occasionally inflated up to 6–9 μm in diam., basidia-bearing hyphae well-differentiated, 2–6 μm in diam., often showing a zigzag-like branching pattern. Crystals accidental, angular, small. Cystidia occasionally present, hyaline or brownish, thin- or slightly thick-walled, narrowly clavate or gradually tapering to the apex, rarely constricted in the middle, 23–44 × 6–9 μm, sometimes with one or two inner septa. Hyphidia richly branched, with a hyphoid or nodulose stem, 20–60 × 2–8 μm, and hyaline or grayish-brownish apical branches, 1–1.5 μm in diam., covering basidia and forming a continuous layer up 40 μm thick. Probasidia clavate or somewhat tapering, 15–28 × 6–9 μm. Basidia four-celled, ellipsoid-ovoid, more rarely broadly ellipsoid, sessile, (13 –) 14–21 (– 22.5) × (9.3 –) 9.6–15.9 (– 16.2) μm (n = 25 / 2), thin-walled or with a distinct wall, embedded, occasionally with a tapering, stalk-like base, up to 8 × 3 μm, sterigmata up to 35 × 2–3.5 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, often slightly curved, (11.0 –) 11.2–15.1 (– 15.3) × (5.0 –) 5.1–6.2 (– 6.3) μm (n = 60 / 2), L = 12.72–13.00, W = 5.62–6.29, Q = 2.08–2.27.</p><p>Remarks.</p><p>Exidia repleta is introduced here based on three collections from the southern part of France, all from dead, hanging branches of Quercus coccifera . It is a resupinate species closely related to E. saturata described below. The species show small (3–5 bp) differences in the ITS region but their RPB 2 sequences are much more divergent (up to 25 bp difference). Combined with clear morphological differences, we feel confident in introducing them as two separate species. Macroscopically, E. repleta differs from E. saturata in having smaller basidiomata and grayish-white (without bluish or violet hues) hymenial surface. In the microscope, the two species are distinguishable primarily due to their spore shape and size.</p><p>Tegmenticium peritrichum redescribed below shows a certain morphological similarity to E. repleta, mainly due to its gelatinous basidiomata covered by grayish removable pruina, as well as predominantly broadly cylindrical basidiospores. However, it can be separated from E. repleta (as well as E. saturata) due to its corticioid basidiomata and more evenly outlined, thin-walled subicular and subhymenial hyphae. Moreover, basidia-bearing hyphae of T. peritrichum are mostly poorly differentiated while they are easily detectable in the two Exidia spp. The epihymenial layer is rather loose and rarely exceeds 20 μm thick in T. peritrichum; in E. repleta and E. saturata, it is quite dense and at least 30–40 μm thick. Differences of E. repleta from E. delita and E. plumbescens are mentioned under the latter species.</p></div>	https://treatment.plazi.org/id/1937603E4290500EB2AD1FCC82A486F8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
87E22DCF733F5EEDB6D2D37986359F14.text	87E22DCF733F5EEDB6D2D37986359F14.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia saccharina fm. carnea Raitv.	<div><p>Exidia saccharina f. carnea Raitv., Plants and Animals of the Far East: 116, 1971</p><p>Holotype.</p><p>Russia • Krasnoyarsk Reg.: Mana Dist., Oreshnoye, Picea obovata, 6 Sep 1958, Parmasto (TAAM 9819 *, studied) .</p><p>The ITS sequence obtained from the type of material of E. saccharina f. carnea confirms that it should be treated as a synonym of Ditangium cerasi ( Sebacinales).</p></div>	https://treatment.plazi.org/id/87E22DCF733F5EEDB6D2D37986359F14	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
12A0AC9A5D3B55628DC51D0BAE8D0E38.text	12A0AC9A5D3B55628DC51D0BAE8D0E38.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia saturata Spirin & Viner 2026	<div><p>Exidia saturata Spirin &amp; Viner sp. nov.</p><p>Figs 20 H, 23 C</p><p>Holotype.</p><p>France • Var: Toulon, Mont Faron, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=5.9248&amp;materialsCitation.latitude=43.1437" title="Search Plazi for locations around (long 5.9248/lat 43.1437)">Plateau des Jésuits</a>, 43.1437; 5.9248, Rosmarinus officinalis (dead stem), 23 Jan 2026, Spirin 18746 * (H, isotype – PC) .</p><p>Etymology.</p><p>Saturatus (Lat., adj.) – saturated; in reference to hygroscopic basidiomata.</p><p>Description.</p><p>Basidiomata annual, effused, first small, gregarious, adpressed-orbicular, 0.5–1.5 mm in diam., then partly or completely fusing together and forming compound basidiomata, up to 15 cm in the longest dimension, gelatinous, opaque, 0.2–0.5 mm thick. Hymenial surface smooth or tuberculate, entirely covered by bluish- or violet-gray, easily removable pruina, often with brown flecks, in older basidiomata partly disappearing and showing a darker, vinaceous-brownish inner layer. Margin clearly delimited, adnate, often somewhat elevated and lobate, concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or brownish, thin- to slightly thick-walled, mostly interwoven, anastomosing, 1–5 μm in diam., occasionally strongly inflated (up to 6–8 μm in diam.), subhymenial hyphae hyaline or brownish, thin-walled or with a distinct wall, predominantly ascending, 1.5–3 μm in diam., occasionally inflated up to 4–5 μm in diam., basidia-bearing hyphae well-differentiated, 2–3 μm in diam., often showing a zigzag-like branching pattern. Crystals accidental, angular, small. Cystidia occasionally present, hyaline or grayish-brownish, thin- or slightly thick-walled, narrowly clavate or gradually tapering to the apex, occasionally constricted, 18–52 × 5–11 μm. Hyphidia richly branched, with a hyphoid or nodulose stem, 20–50 × 2.5–7 μm, and hyaline or brownish apical branches, 0.8–1.5 μm in diam., covering basidia and forming a continuous layer up 60 μm thick. Probasidia broadly clavate or somewhat tapering, 13–19 × 5–9 μm. Basidia four-celled, ellipsoid-ovoid or broadly ellipsoid, sessile, (13 –) 13.5–17 (– 17.5) × (10.1 –) 10.2–13.3 (– 13.5) μm (n = 20 / 2), thin-walled, sometimes obliquely septate, embedded, occasionally with a tapering, stalk-like base, up to 5 × 2.5 μm, sterigmata up to 30 × 2–4 μm. Basidiospores thin-walled, narrowly to broadly cylindrical, often distinctly curved, (9.2 –) 9.8–14.9 (– 15.2) × (3.9 –) 4.0–5.1 (– 5.2) μm (n = 60 / 2), L = 12.11–12.67, W = 4.53–4.71, Q = 2.59–2.82.</p><p>Remarks.</p><p>Exidia saturata is described here as a sister species of E. repleta . It differs from the latter species primarily due to the presence of bluish or violet hues in the basidiome color and in having narrower basidiospores. At large part, the originally adpressed-orbicular basidiomata of E. saturata completely fuse together and form rather extensive compound crust-like fructifications, while they mainly remain discernible and normally quite small in E. repleta .</p><p>Exidia saturata and E. repleta occur in the same localities in the Mediterranean. Two of our specimens of E. saturata were collected from dead stems of Rosmarinus . The GenBank sequence AJ 427409 labelled as Sebacina umbrina D. P. Rogers belongs to E. saturata; its source is a specimen collected from Cistus monspelliensis in France. In turn, E. repleta has been so far found only on Quercus .</p></div>	https://treatment.plazi.org/id/12A0AC9A5D3B55628DC51D0BAE8D0E38	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
8F81AAE3FB83541393A6228EF96FB766.text	8F81AAE3FB83541393A6228EF96FB766.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia semiorbis Malysheva 2026	<div><p>Exidia semiorbis Malysheva sp. nov.</p><p>Figs 23 D, 24 A</p><p>Holotype.</p><p>Russia • Primorie Reg.: Shkotovo Dist., Ussuri Nat. Res., <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=132.59026&amp;materialsCitation.latitude=43.64769" title="Search Plazi for locations around (long 132.59026/lat 43.64769)">Peishula</a>, 43.64769; 132.59026, Salix sp. (fallen log), 16 Aug 2011, Malysheva (LE F-262976 *) .</p><p>Etymology.</p><p>Semiorbis (Lat., noun) – semicircle.</p><p>Description.</p><p>Basidiomata annual, button-shaped or cupulate-orbicular, up to 1 cm in diam., narrowly attached, up to 0.5 cm thick, gelatinous. Hymenial surface even, smooth or rarely bearing scattered granular projections up to 0.1 mm long, pinkish- to reddish-brown, in dry condition dark-brown. Abhymenial surface smooth or covered by scattered minute dots, reddish-brown. Margin free, concolorous with hymenial surface, entire, evenly rounded or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin-walled or with a distinct wall, interwoven, anastomosing, 2–5 μm in diam., subhymenial hyphae hyaline, thin-walled or with a distinct wall, ascending or interwoven, 2–4 (5) μm in diam., basidia-bearing hyphae 2–5 μm in diam. Hyphidia scattered, with a hyaline, hyphoid or tortuous stem, 2.5–5 μm in diam., and hyaline apical branches, 0.5–2 μm in diam. Probasidia tapering, 15–30 × 5–9.5 μm. Basidia four-celled, broadly clavate to ellipsoid-ovoid, more rarely subglobose, (10 –) 11.5–15 (– 16) × (6.1 –) 6.6–8.2 (– 9.0) μm (n = 20 / 2), sterigmata up to 40 × 2.5–3 μm. Basidiospores allantoid to narrowly cylindrical, distinctly curved, (10.2 –) 11.0–15.6 (– 16.9) × (2.7 –) 2.8–4.2 (– 4.3) μm (n = 38 / 2), L = 12.19–13.95, W = 3.11–3.54, Q = 3.92–3.99.</p><p>Remarks.</p><p>Exidia semiorbis is introduced here as a new species from Far East Russia where it inhabits fallen branches of deciduous trees. Morphologically, it is most similar to the East Asian E. uvapassa . Exidia semiorbis differs from the latter species in having lighter-colored basidiomata and in lacking an epihymenial membrane. Moreover, E. uvapassa has much larger basidia than E. semiorbis, reaching 25 μm or even more. Phylogenetically, these species are not closely related (Fig. 7). Differences between E. semiorbis and the superficially similar D. repanda are discussed in the remarks on the genus Exidia above.</p></div>	https://treatment.plazi.org/id/8F81AAE3FB83541393A6228EF96FB766	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
83068EC904035A79AB35144CE43C688B.text	83068EC904035A79AB35144CE43C688B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia spiculata Schwein.	<div><p>Exidia spiculata Schwein., Transactions of the American Mycological Society 4: 185, 1832</p><p>Fig. 23 E</p><p>= Exidia glandulosa f. populi Neuhoff, Arkiv för Botanik 28 A (1): 13. Holotype. Sweden. Uppland: Uppsala, Lassby backar, Populus tremula, 10 Apr 1884, Romell 4388 (S F 207857, studied) .</p><p>= Exidia inflata Cazenave &amp; G. Gruhn, Bulletin de la Société Mycologique de France 140: 214, 2024. Holotype. France. Hautes-Pyrénées: Séméac, Bois de Labarthe, Populus tremula, 26 Feb 2022, Cazenave (LIP GG-240916-001 *, isotype – H, studied) .</p><p>Holotype.</p><p>USA. Pennsylvania: Bethlehem, Platanus sp. (cut surface of log), [no collecting date indicated], Schweinitz 1101 (PH 00062438, studied) (Fig. 23 E) .</p><p>Description.</p><p>Basidiomata annual, at first cushion- or button-shaped, then adpressed-orbicular, up to 2 cm in diam., broadly attached, often in groups, finally fusing together and forming compound effused basidiomata but rarely reaching 4 cm in the longest dimension, up to 0.5 cm thick, gelatinous. Hymenial surface uneven or variably folded, brownish-gray to brownish-black, rarely with indistinct warts normally associated with embedded white mineral inclusions, in older basidiomata sometimes fading to yellowish-brown, in dry condition nearly black. Abhymenial surface smooth or rarely minutely dotted, concolorous with hymenial surface. Margin free, concolourous with hymenial surface, entire, even.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or grayish, thin- to slightly thick-walled, interwoven, anastomosing, occasionally encrusted, 0.5–5 μm in diam., sometimes inflated up to 7.5 μm in diam., subhymenial hyphae hyaline or grayish, thin- to slightly thick-walled, predominantly ascending, 1–4 μm in diam., basidia-bearing hyphae thin- to slightly thick-walled, 2–5 μm in diam. Hyphidia with a grayish or brownish, hyphoid or nodulose stem, 2.5–7 μm in diam., and hyaline or brownish-gray apical branches, 0.8–1.5 μm in diam., forming a continuous layer up to 60 μm thick and sometimes covered by masses of angular crystals. Probasidia tapering or clavate, 11–18 × 4–8 μm. Basidia four-celled, ellipsoid-ovoid, (9.5 –) 10–14 (– 15.5) × (7.1 –) 7.3–10.0 (– 10.2) μm (n = 50 / 4), sterigmata up to 15 × 1–2 μm. Basidiospores narrowly cylindrical to allantoid, slightly or distinctly curved, (9.8 –) 10.2–15.6 (– 15.7) × (2.8 –) 2.9–4.2 (– 4.3) μm (n = 173 / 6), L = 11.91–13.60, W = 3.44–3.77, Q = 3.41–3.74, normally aguttulate.</p><p>Remarks.</p><p>Exidia spiculata is one of the nigrescent Exidia spp. belonging to the E. pithya complex (Figs 10, 11). It seems that it is widely distributed in the cold temperate and boreal ecosystems of Eurasia but overlooked. Exidia spiculata inhabits dead branches or just fallen, corticated logs of many deciduous trees but with a certain preference for Salicaceae . Morphologically and phylogenetically, it is very close to the East Asian E. subglandulosa which, however, has wider basidiospores (see below). The superficially similar E. pithya has on average wider basidiospores than E. spiculata . They are more allantoid and normally aguttulate in the latter species. In E. pithya, the spores are always filled with numerous and easily detectable oil droplets (Fig. 19). Moreover, E. spiculata never produces spine-like projections on the hymenial surface, while these outgrowths are typically present in E. pithya .</p><p>Exidia spiculata was first described by Schweinitz (1832) from Bethlehem, Pennsylvania. Coker (1920) studied the type material of E. spiculata and concluded that it was of no value. On the contrary, Burt (1921) found the type of E. spiculata to be identifiable. He was able to find basidiospores and associate the type specimen with a few other collections from the US North-East. Burt stressed another macroscopic feature of E. spiculata which was missing in the original description, i. e. the presence of white mineral grains on the hymenial surface, easily detectable without magnification. Both Coker and Burt were misled by Schweinitz’s remark in the protologue that E. spiculata has a papillose surface (‘ papillis frequentibus in superficie’ – Schweinitz, ibid.). They thought that this detail referred to papillae on the hymenial surface which they could not find in the type specimen. In fact, this part of Schweinitz’s description refers to the abhymenial surface which is, according to our observations, covered by small, densely arranged papillate projections, ca. 50 × 50 μm. The hymenial surface in the type collection is folded but devoid of any other kind of outgrowths.</p><p>Neuhoff (1936 a) placed E. spiculata in the synonyms of E. glandulosa sensu auct. (= E. pithya in the present study). The same year, he described E. glandulosa f. populi from Sweden (Neuhoff 1936 b). In the description of this form, Neuhoff emphasized its minutely dotted abhymenial surface (‘ subtus punctato-scabra’), i. e. the same feature mentioned by Schweinitz for his E. spiculata, as well as its folded hymenial surface lacking any other projections (‘ disco plano, dein subcostato’). The type specimen of E. glandulosa f. populi perfectly matches other specimens of E. spiculata studied by us. We should note, however, that we were able to observe the papillose abhymenial surface only in a few specimens of E. spiculata (including the holotype) while it is apparently smooth in most collections studied by us. This trait is, therefore, of minor value to distinguish between E. spiculata and E. pithya . As for easily visible mineral grains, we could find them only in senescent, coalescent individuals of E. spiculata . They were both embedded and exposed. Nevertheless, if present, they give an additional clue for recognizing E. spiculata vs. E. pithya because old specimens of both species are often sterile. Basidiomata of Exidia pithya may also contain mineral concretions. However, they are small, visible only under lens, and as a rule embedded.</p></div>	https://treatment.plazi.org/id/83068EC904035A79AB35144CE43C688B	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
37245CC175255648B0C9B757B32E537E.text	37245CC175255648B0C9B757B32E537E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia straminea Berk.	<div><p>Exidia straminea Berk., Hooker’s Journal of Botany 3: 19, 1851</p><p>Figs 23 F, 24 B</p><p>Lectotype</p><p>(iconotype) (selected here, MBT 10031440). Table I, fig. 4 in Hooker’s Journal of Botany 3, 1851.</p><p>Epitype (selected here, MBT 10031441). France. Aveyron: Millau, Le Monna, Amelanchier ovalis (dead hanging branch), 23 Feb 2025, Spirin 18148 * (H) .</p><p>Description.</p><p>Basidiomata annual, cupulate-orbicular, up to 3 cm in diam., narrowly attached, later partly fusing together but remaining separable, up to 1 cm thick, gelatinous, older basidiomata sometimes nearly cerebriform. Hymenial surface even or variably folded, sometimes bearing scattered granular projections up to 0.1 mm long, at first amber-yellow or ochraceous-brownish, later bright reddish-brown, in dry condition darkening to dark brown or brownish-black. Abhymenial surface rough, covered by tightly arranged dots, yellowish-ochraceous to reddish-brown. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, occasionally bearing scattered colorless encrustation, thin- to slightly thick-walled, interwoven, anastomosing, 1–6 μm in diam., subhymenial hyphae hyaline or brownish, occasionally sparsely encrusted, thin-walled or with a distinct wall, ascending or interwoven, 1.5–4 μm in diam., sometimes producing large bubble-like segments up to 15 μm in diam., basidia-bearing hyphae thin-walled or with a distinct wall, 2–5 μm in diam. Hyphidia with a hyaline or brownish, occasionally encrusted hyphoid stem, 1.5–8 μm in diam., and hyaline apical branches, 1–1.5 μm in diam., embedded in brownish gelatinous matrix and forming a continuous layer up to 40 μm thick. Probasidia distinctly tapering or clavate, 9–24 × 4–7 μm. Basidia four-celled, ellipsoid-ovoid, more rarely broadly clavate, sometimes obliquely septate, (10.5 –) 11–18 (– 18.5) × (5.8 –) 6.2–11.0 (– 11.1) μm (n = 80 / 8), sterigmata up to 40 × 1–1.5 μm. Basidiospores narrowly cylindrical to allantoid, distinctly curved, occasionally two-or three-celled, (9.2 –) 9.3–15.7 (– 15.8) × (2.8 –) 2.9–4.1 (– 4.3) μm (n = 260 / 9), L = 11.32–13.86, W = 3.18–3.72, Q = 3.35–4.13.</p><p>Remarks.</p><p>Exidia straminea is a look-alike of E. recisa distributed in the southern part of Europe. It inhabits dead branches and thin stems of various shrubs but seemingly never occurs on Salix spp. Morphologically, it can be separated from E. recisa in having amber-yellow or light-brown basidiomata without any tints of red, as well as by its shorter basidiospores. Another similar species occurring in the same geographic area on deciduous hosts is E. impressa . It has much darker basidiomata than E. straminea and occasionally possesses distinctive sharp projections on the hymenial surface. Microscopically, it can be separated from E. straminea in having two types of hyphidia. The basidiospores of both species are nearly identical.</p><p>Exidia straminea was described from southern France (Berkeley 1851). We could not trace the type specimen of this species. The only extant authentic material of E. straminea is a microscopic drawing published by Berkeley. We therefore select it as a lectotype (iconotype) of E. straminea . Unfortunately, it provides no worthwhile information for species recognition. The “ 2–3 - septate moniliform threads ” depicted by Berkeley may equally be bubble-like segments of subhymenial hyphae or immature basidia. Fortunately, the macroscopic part of the protologue is rather clear and it evidently refers to a pale-colored specimen of E. straminea as it is reintroduced above. We designate an epitype to maintain our understanding of this species. The description of E. impressa by Bourdot and Galzin (1927) mostly refers to E. straminea . This species was misidentified by Wu et al. (2020) as E. repanda .</p></div>	https://treatment.plazi.org/id/37245CC175255648B0C9B757B32E537E	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
BAA9DFFF538D521A87258E974D8E7D2F.text	BAA9DFFF538D521A87258E974D8E7D2F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia subglandulosa F. Wu, L. F. Fan & S. Y. Ye	<div><p>Exidia subglandulosa F. Wu, L. F. Fan &amp; S. Y. Ye, Mycological Progress 19: 862, 2020</p><p>Holotype.</p><p>China • Qinghai: Zeku, Maixiu, Salix cheilophila, 12 Jul 2019, Wu 270 * (BJFC) .</p><p>Exidia subglandulosa is closely related to E. spiculata (Figs 10, 11). The species are very similar morphologically, and the only reliable difference between them seems to be the basidiospore width. The spores are on average wider in E. subglandulosa (see description in Ye et al. 2020) than in E. spiculata . Exidia subglandulosa is so far known only from China.</p></div>	https://treatment.plazi.org/id/BAA9DFFF538D521A87258E974D8E7D2F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
5FDAC009473C5930AECA0DFC70462126.text	5FDAC009473C5930AECA0DFC70462126.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia tanzanica Spirin & Ryvarden 2026	<div><p>Exidia tanzanica Spirin &amp; Ryvarden sp. nov.</p><p>Fig. 23 G</p><p>Holotype.</p><p>Tanzania • Arusha Prov.: Arusha Nat. Park, Mt. Meru (crater side), dead wood, 24 Jun 1994, Ryvarden 34395 * (O, isotype – H) .</p><p>Etymology.</p><p>Tanzanicus (Lat., adj.) – Tanzanian.</p><p>Description.</p><p>Basidiomata annual, effused, up to 7 cm in the widest dimension, gelatinous, semitranslucent, 0.5–1.5 mm thick. Hymenial surface dark brownish-gray to brownish-black in fresh condition, corneous and nearly black in dry specimens, covered by densely arranged, grayish, blunt projections, 100 × 80 μm, 4–10 per mm. Margin sharply delimited, detaching, concolorous with hymenial surface, always more or less clearly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, thin-walled or with variably thickened, gelatinized walls, interwoven, 1.5–4 (5) μm in diam., subhymenial hyphae hyaline or grayish, thin-walled or with a distinct, gelatinized wall, ascending or interwoven, agglutinated, 1.5–3 μm in diam., basidia-bearing hyphae 2–5 μm in diam. Crystals accidentally present, angular, small. Hyphidia richly branched, with a hyphoid or subfusiform stem, 2–6 μm in diam., and grayish or brownish-black apical branches, 1–2 μm in diam., forming a continuous layer up to 30 μm thick. Probasidia tapering to narrowly clavate, 13–29 × 6.5–8.5 μm. Basidia four-celled, narrowly ellipsoid-ovoid, sessile, more or less clearly tapering to the base, (16 –) 17.5–23.5 (– 24) × (9.6 –) 10.2–13.5 (– 13.8) μm (n = 20 / 1), slightly thick-walled, embedded, sometimes obliquely septate, sterigmata up to 10 × 2.5–3 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, often distinctly curved, rarely almost narrowly ovoid, (9.1 –) 9.2–12.2 (– 12.6) × (4.2 –) 4.4–6.1 (– 6.2) μm (n = 20 / 1), L = 10.97, W = 5.32, Q = 2.08.</p><p>Remarks.</p><p>Exidia tanzanica is introduced here as a close relative of E. japonica and other species recently assigned to the genus Tremellochaete (e. g., T. atlantica and T. australiensis). Due to its nearly black basidiomata covered by densely arranged, obtuse hymenial projections, E. tanzanica is strongly reminiscent of E. japonica . However, the latter species differs from E. tanzanica in having narrower basidiospores (4–5 μm wide) and smaller basidia (up to 15 μm long). See also remarks on Exidia purpureocinerea (under Excluded taxa).</p></div>	https://treatment.plazi.org/id/5FDAC009473C5930AECA0DFC70462126	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
3BE132DBA1FB59968DD233C0BA0161DF.text	3BE132DBA1FB59968DD233C0BA0161DF.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia tenax Cooke	<div><p>Exidia tenax Cooke, Grevillea 8 (46): 57, 1879</p><p>Holotype.</p><p>New Zealand. Southland: Winton, on branches, [no collecting date], Berggren 111 (K (M) 1435722, studied) .</p><p>After studying the type material of E. tenax, we concluded that it is yet another species in the Exidia japonica complex. The darker basidiomata and narrower basidiospores of E. tenax (measured as (10.1 –) 10.5–15.4 (– 16.3) × (3.4 –) 4.1–5.2 (– 5.4) μm (n = 23 / 1), L = 12.51, W = 4.59, Q = 2.74) preclude its conspecificity with Tremellochaete australiensis F. Wu et al. recently described from Australia (Tohtirjap et al. 2023). It is possible that E. novozealandica introduced from the same geographic area is a younger synonym of E. tenax . Alternatively, E. novozealandica may turn out to be an older name for T. australiensis . Solving these questions requires a thorough study of the E. japonica group in Oceania, as well as the type study of E. novozealandica .</p></div>	https://treatment.plazi.org/id/3BE132DBA1FB59968DD233C0BA0161DF	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
ED5154B274405AAD95BFC8B17C67324E.text	ED5154B274405AAD95BFC8B17C67324E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia truncata Fr.	<div><p>Exidia truncata Fr., Systema Mycologicum 2: 224, 1822</p><p>Figs 23 H, 24 C</p><p>Neotype</p><p>(designated here, MBT 10031443). Sweden • Västergötland: Göteborg, Guldheden, Quercus robur (dead hanging branch), 28 Dec 2024, Spirin 18029 * (GB, duplicate – H) .</p><p>Description.</p><p>Basidiomata annual, button-shaped or adpressed-orbicular, narrowly attached, rarely with a reduced stalk-like base up to 0.5 cm long, later turbinate or nearly cupulate, up to 5 cm in diam., up to 1.5 cm thick, gelatinous. Hymenial surface uneven or indistinctly folded, covered by rather regularly arranged spine-like black projections up to 0.2 mm long, dark gray to brownish-gray, later brownish-black, in dry condition completely black. Abhymenial surface rough, covered by densely arranged blackish dots or sharp outgrowths up to 0.1 mm long, grayish-brown. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or rarely grayish, thin- to distinctly thick-walled, predominantly interwoven, anastomosing, 0.5–6 μm in diam., subhymenial hyphae hyaline to grayish or brownish, thin-walled or with a distinct wall, ascending or interwoven, 1.5–4 μm in diam., basidia-bearing hyphae 1.5–5 μm in diam. Hyphidia with a hyaline or grayish-brownish hyphoid stem, 1.5–8 μm in diam., and hyaline or pale grayish apical branches, 0.5–1 μm in diam., forming a continuous layer up to 50 μm thick. Probasidia tapering to subfusiform, 14–22 × 5–10.5 μm. Basidia four-celled, ellipsoid-ovoid, thin-walled, (14.5 –) 15–22 (– 23) × (9.1 –) 9.3–13.3 (– 13.7) μm (n = 30 / 3), sterigmata up to 50 × 1.5–2 μm. Basidiospores narrowly cylindrical to allantoid, distinctly to strongly curved (lunate), (13.0 –) 13.7–20.1 (– 20.4) × (4.3 –) 4.4–6.2 (– 6.3) μm (n = 90 / 3), L = 17.12–18.03, W = 4.89–5.06, Q = 3.44–3.57.</p><p>Remarks.</p><p>Exidia truncata was described by Fries (1822). However, its identity remained controversial, mainly because no original specimens or illustrations were extant. Neuhoff (1936 b) applied the name E. truncata to an Exidia with adpressed-orbicular or turbinate basidiomata occurring mainly on Quercus branches in temperate Europe. Our data show that Neuhoff’s concept of E. truncata covers two similar and closely related species. The first species has a hairy abhymenial surface, while it is minutely dotted or scabrose (covered by tiny, densely arranged sharp warts) in the second one. Moreover, the second species has longer basidiospores than the first one. The ongoing convention, including recent DNA studies, attributed the epithet E. truncata to the first species (Weiß and Oberwinkler 2001; Ye et al. 2020; Gruhn et al. 2024). However, this attribution is at odds with Fries’ concept of the species. He described E. truncata as ‘ subtus punctato-scabra’ (Fries 1822: 224) while all forms with a hairy abhymenial surface were addressed by him to E. glandulosa (ibid., ‘ subtus cinerea subtomentosa’). We therefore reintroduce the name E. truncata for the second of the two above-mentioned species; the first species is redescribed and typified above as E. glandulosa .</p><p>Exidia truncata seems to be rather common in the south-western part of Sweden. The GenBank sequence KU 973844 from Tunisia belongs to this species, too. It means that the species is most likely widely distributed and just overlooked. Fries observed E. truncata growing in the winter, and this fits our observations. The basidiomata of E. truncata start developing in December and completely disappear by the end of April. In contrast, the similar E. glandulosa can be collected throughout the year, although it sporulates mainly in winter or early spring. All our records of E. truncata came from hanging or recently fallen branches of Quercus robur . Fries (1822) stated that he collected E. truncata from Tilia twigs. It is so far uncertain whether he misidentified the host tree or whether E. truncata can inhabit host trees other than Quercus . The third, equally possible option is that Fries’ concepts of both E. glandulosa and E. truncata were intertwining – a suggestion made by Donk (1966) and discussed above under E. glandulosa . Whichever the case is, it does not influence the neotype selection guided by the most reliable feature distinguishing the two species, namely the character of the abhymenial surface.</p></div>	https://treatment.plazi.org/id/ED5154B274405AAD95BFC8B17C67324E	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
1539721AB6395FE9AD529AB78F82FFE3.text	1539721AB6395FE9AD529AB78F82FFE3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia umbrinella Bres.	<div><p>Exidia umbrinella Bres., Fungi Tridentini 2 (14): 98, 1900</p><p>Figs 23 I, 24 D</p><p>Lectotype</p><p>(selected here, MBT 10031444). Italy • Trentino-Alto Adge: Trento, Pellizzano, Val di Sole, Abies alba, 1888 Bresadola (S F 20648, studied) .</p><p>Description.</p><p>Basidiomata annual, button-like to cupulate-orbicular, up to 2 cm in diam., narrowly attached, up to 0.5 cm thick, gelatinous. Hymenial surface even or folded, rarely bearing scattered granular projections up to 0.1 mm long, at first ochraceous- to reddish-brown, later dark brown, in dry condition darkening to nearly black. Abhymenial surface rough, covered by tightly arranged dots, reddish-brown or dark brown. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or yellowish, thin-walled or with variably thickened, gelatinized walls, interwoven or subparallel, anastomosing, 1–5 μm in diam., subhymenial hyphae hyaline or yellowish-brownish, thin-walled or with a distinct wall, predominantly ascending, 1–3 μm in diam., basidia-bearing hyphae thin-walled or with a distinct wall, 2–4 μm in diam. Hyphidia with a hyaline or brownish, often sinuous hyphoid stem, 3–5 μm in diam., and hyaline or brownish apical branches, 1–2 μm in diam., embedded in yellowish-brownish gelatinous matrix and forming a continuous layer up to 20 μm thick. Probasidia tapering or clavate, 9–13.5 × 4.5–5.5 μm. Basidia four-celled, narrowly ellipsoid-ovoid, (9.5 –) 10–13.5 (– 14) × (6.2 –) 6.7–9.8 (– 10.8) μm (n = 42 / 2), sterigmata up to 30 × 1–2 μm. Basidiospores narrowly cylindrical to allantoid, distinctly curved, (8.7 –) 9.0–13.2 (– 13.8) × (2.7 –) 2.8–3.8 (– 4.0) μm (n = 52 / 2), L = 11.29–12.00, W = 3.10–3.33, Q = 3.41–3.90.</p><p>Remarks.</p><p>Exidia umbrinella is a member of the E. recisa complex (Fig. 9). It is the only species in this group known so far to occur on coniferous hosts. The substrate, as well as rather short basidiospores, provide sufficient grounds to separate E. umbrinella from the otherwise very similar E. recisa . This species was described by Bresadola (1900) based on a rather large set of specimens from Italy and Slovakia. Abies spp. and Larix decidua were mentioned as its substrates. Here we select the best-preserved, fertile specimen of E. umbrinella from Stockholm as a lectotype of this species. Bourdot and Galzin (1927) reported E. umbrinella from France. Neuhoff (1935) published records of E. umbrinella from Central Europe which seem to belong to this species, except for his records on Pinus in Germany most likely referring to Ulocolla saccharina (see below). Here we report E. umbrinella from the Caucasus.</p></div>	https://treatment.plazi.org/id/1539721AB6395FE9AD529AB78F82FFE3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
EFC09F504C8A5728A2D916FCEE2E09F2.text	EFC09F504C8A5728A2D916FCEE2E09F2.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia uvapassa Lloyd	<div><p>Exidia uvapassa Lloyd, Mycological Writings 5: 774, 1918</p><p>Fig. 24 E</p><p>Lectotype</p><p>(selected by Stevenson and Cash 1936: 32). Japan • Kobe, [no collecting date], J. E. A. Lewis (Lloyd’s herbarium # 33506) (BPI) .</p><p>For a description, see Malysheva (2012).</p></div>	https://treatment.plazi.org/id/EFC09F504C8A5728A2D916FCEE2E09F2	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
8B83B0A1E1C158C192B1710D0CE88856.text	8B83B0A1E1C158C192B1710D0CE88856.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia yadongensis F. Wu, Qi Zhao, Zhu L. Yang & Y. C. Dai	<div><p>Exidia yadongensis F. Wu, Qi Zhao, Zhu L. Yang &amp; Y. C. Dai, Mycosystema 39: 1210, 2020</p><p>Holotype.</p><p>China • Hubei: Shennongjia, Ulmus sp., 16 Oct 2016, Dai 17268 * (BJFC) .</p><p>For a description, see Wu et al. (2020). This species was introduced as a member of the E. recisa complex closely related to the North American E. crenata . Here we report it from the Russian Far East. See further remarks under E. crenata above. Exidia impressa, occurring in the same geographic area and on the same set of hosts, can be separated from E. yadongensis by its darker basidiomata with occasional sharp hymenial projections and the presence of two types of hyphidia.</p></div>	https://treatment.plazi.org/id/8B83B0A1E1C158C192B1710D0CE88856	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
E67E65E820B458B3A92740859FFCA319.text	E67E65E820B458B3A92740859FFCA319.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidia zelleri Lloyd	<div><p>Exidia zelleri Lloyd, Mycological Writings 6: 931, 1920</p><p>Figs 23 J, 24 F</p><p>= Exidia glandulosa f. lobata Neuhoff, Arkiv för Botanik 28 A (1): 13.</p><p>= Exidia glandulosa f. nannfeldtii Neuhoff, Arkiv för Botanik 28 A (1): 14.</p><p>Holotype.</p><p>USA. Oregon: Benton Co., Corvallis, [ Acer sp.], 11 Oct 1919, Zeller 1775 (NY 00738335 – isotype, studied) (Figs 23 J, 24 F) .</p><p>Description.</p><p>Basidiomata annual, at first adpressed-orbicular, narrowly attached, then turbinate or nearly cupulate, up to 1 cm in diam., up to 0.5 cm thick, sometimes partly fusing together and forming compound effused basidiomata, up to 3 cm in the longest dimension, gelatinous. Hymenial surface uneven or indistinctly folded, rarely minutely warted, brownish-black, in dry condition completely black. Abhymenial surface smooth, grayish-brown to brownish-black. Margin free, concolourous with hymenial surface, entire, even or lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline or brownish, predominantly thin-walled, interwoven, anastomosing, 1–5 μm in diam., subhymenial hyphae hyaline to brownish, thin-walled or with a distinct wall, ascending or interwoven, 1–4 μm in diam., basidia-bearing hyphae 2–6 μm in diam. Hyphidia with a hyaline or brownish hyphoid stem, 2–11 μm in diam., and hyaline or brownish apical branches, 0.5–2 μm in diam., forming a continuous layer up to 100 μm thick. Probasidia broadly clavate to tapering or subfusiform, 15–29 × 6–11.5 μm. Basidia four-celled, ellipsoid-ovoid to narrowly ovoid, thin-walled, (14 –) 14.5–26 (– 28.5) × (8.9 –) 9.0–15.1 (– 15.3) μm (n = 71 / 5), sterigmata up to 50 × 1.5–2.5 μm. Basidiospores narrowly cylindrical or cylindrical to allantoid, slightly to distinctly curved, (13.0 –) 13.2–21.9 (– 22.2) × (4.1 –) 4.2–7.0 (– 7.2) μm (n = 140 / 5), L = 16.49–18.68, W = 4.81–6.08, Q = 2.92–3.55.</p><p>Remarks.</p><p>Exidia zelleri is a member of the E. glandulosa complex (Figs 1, 2, 8). Macroscopically, it is very different from the two other species of this group, E. glandulosa and E. truncata, due to its rather small basidiomata with smooth hymenial and abhymenial surfaces (Fig. 24). However, its large basidia and basidiospores are strongly reminiscent of those of the two aforementioned species. Exidia zelleri is widely distributed in the northern hemisphere but rarely collected, most likely due to its quite insignificant fructifications. It occurs predominantly on dead wood of Salicaceae and rarely also on other host trees ( Acer and Alnus). Specimens of E. zelleri are often sterile. They can be nonetheless identified as belonging to this species due to the nearly smooth hymenial surface without spine-like projections, as well as the large basidia.</p><p>Exidia zelleri was described by Lloyd (1920) from Oregon, USA. The host species was identified by the original collector as Sambucus . However, the later re-examination by H. C. Klett (herbarium note in NY from August 26 th, 1963) showed that the host tree was actually Acer sp. The isotype of E. zelleri in NY is still in a good condition, with rather numerous, turgid, allantoid or narrowly cylindrical spores, ca. 14–18 × 4–5.5 μm. These spore dimensions, in combination with the lack of hymenial projections, definitely preclude any other nigrescent Exidia species dealt with in this paper. Neuhoff (1936 b) introduced two forms of E. glandulosa sensu auct. from northern Sweden, f. lobata and f. nannfeldtii . Based on his descriptions, they are both considered here as belonging to E. zelleri . Torkelsen (1972) reported f. lobata from Norway. The basidial and basidiospore measurements given by her certainly point to E. zelleri .</p></div>	https://treatment.plazi.org/id/E67E65E820B458B3A92740859FFCA319	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
6EECB58775EA5B77B57F7CC5B18626E7.text	6EECB58775EA5B77B57F7CC5B18626E7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis citrina Hauerslev	<div><p>Exidiopsis citrina Hauerslev, Mycotaxon 49: 221, 1993</p><p>Holotype.</p><p>Denmark • Hovedstaden: Lyngby-Taarbæk, Ørholm, Salix sp. (?), 19 Nov 1976, Hauerslev 5257 (C 19751, studied) .</p><p>Exidiopsis citrina was introduced based on a single specimen from Denmark (Hauerslev 1993). Rather small, predominantly pyriform basidiospores, as well as constantly two-celled basidia with relatively thick sterigmata are atypical for the Auriculariaceae . This species is definitely not a member of Exidiopsis as reintroduced above but its taxonomic position cannot be defined without DNA data.</p></div>	https://treatment.plazi.org/id/6EECB58775EA5B77B57F7CC5B18626E7	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
90625C14199851EDA02992EB4A5E47CF.text	90625C14199851EDA02992EB4A5E47CF.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis diversa K. Wells	<div><p>Exidiopsis diversa K. Wells, Mycologia 79: 280, 1987</p><p>Holotype.</p><p>Canada • British Columbia: Princeton, Asp Creek, Populus sp., 25 May 1979, Wells 2769 (BPI 871728 – isotype, studied) .</p><p>Morphological and cultural descriptions of E. diversa were provided by Wells (1987). Microscopic traits (shape and size of basidia and basidiospores) put it close to Tegmenticium peritrichum although the basidiomata of E. diversa are much thinner than in the latter species, ca. 0.05 mm thick, and they lack the differentiated cystidia characteristic of T. peritrichum . This species deserves further study with the use of DNA methods.</p></div>	https://treatment.plazi.org/id/90625C14199851EDA02992EB4A5E47CF	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
26560DEFADDF5E4DA51E9F4652B44F41.text	26560DEFADDF5E4DA51E9F4652B44F41.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis effusa (Bref.) Vuillemin	<div><p>Exidiopsis effusa (Bref.) Vuillemin, Bulletin des Séances de la Société des Sciences de Nancy 2 (3): 30, 1890</p><p>Figs 25 A, 26, 27 A, 27 B</p><p>≡ Exidia effusa Bref., Untersuchungen aus dem Gesammtgebiete der Mykologie 7: 94, 1888. Lectotype (selected here, MBT 10031445). Fig. 20, Tafel V in Brefeld, Untersuchungen aus dem Gesammtgebiete der Mykologie 7, 1888. Epitype (selected here, MBT 10031446). Sweden. Västergötland: Göteborg, Guldheden, Salix caprea (fallen log), 14 Mar 2025, Spirin 18205 * (GB) .</p><p>= Exidiopsis quercina Vuillemin, Bulletin des Séances de la Société des Sciences de Nancy 2 (3): 30, 1890. Neotype (selected here, MBT 10031447). France. Lozère: Saint-Etienne-du-Valdonnez, Forêt du Sapet, Fagus sylvatica (fallen branch), 28 Jun 2022, Spirin 15511 * (H) .</p><p>Description.</p><p>Basidiomata annual, effused, usually up to 10 cm in the longest dimension but occasionally exceeding 1 m long (while growing on dead standing logs), at first waxy-gelatinous and watery-grayish, semitranslucent, then more or less distinctly gelatinized, drying to a hardly visible, vernicose crust, up to 0.1 mm thick. Hymenial surface smooth or more often bearing randomly or rather regularly arranged spine-like projections up to 150 × 100 μm, 2–3 per mm, and at least partly covered by a grayish or pale lilac, easily removable pruina. Margin rather sharply delimited, adnate, concolorous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae thin- or slightly thick-walled, gelatinized, mostly interwoven, 2–4 μm in diam., occasionally inflated up to 7–8 μm in diam., subhymenial hyphae thin-walled, predominantly ascending, often agglutinated, 1.5–4.5 μm in diam., occasionally inflated up to 5–6 μm in diam.; basidia-bearing hyphae thin-walled, 1.5–4 μm in diam., sometimes showing a zigzag-like branching pattern. Hyphidia thin-walled, with a hyaline, hyphoid or subfusiform stem, 20–40 × 2–6 μm in diam., and dendroid apical branches 1–1.5 μm in diam., forming a loose continuous layer up to 15 μm thick. Probasidia broadly clavate, 10–30 (– 40) × 5–9 μm. Basidia narrowly ellipsoid-ovoid, four-celled, (10.5 –) 12–21.5 (– 23) × (8.0 –) 8.1–12.3 (– 13.2) μm (n = 80 / 7), thin-walled, embedded, often with a distinctly tapering stalk-like base, up to 7 × 4 μm, sterigmata up to 25 × 2–3 μm. Basidiospores thin-walled, narrowly cylindrical to cylindrical, often distinctly curved, (9.4 –) 9.8–16.8 (– 17.2) × (3.6 –) 3.7–6.2 (– 6.6) μm (n = 210 / 7), L = 11.40–14.26, W = 4.14–5.26, Q = 2.46–2.91.</p><p>Remarks.</p><p>As mentioned above, this species was first described from Germany by Brefeld (1888) as Exidia effusa and later moved to Exidiopsis by Vuillemin (1890). No authentic specimens by Brefeld are extant. We therefore select his illustration accompanying the protologue as a lectotype of this species. Brefeld’s description and drawings are very clear, and the identity of his species is certain. One of the most important macroscopic traits mentioned in the protologue is the presence of papillate outgrowths on the hymenial surface. We were able to observe them in all freshly collected specimens of E. effusa (Fig. 25 A). These projections, as well as (at least partly) gelatinized, semitranslucent basidiomata of E. effusa are the easiest traits to separate it from the closely related E. perflua (see further remarks under that species).</p><p>According to our data, E. effusa has a western distribution in Europe. We studied specimens of E. effusa from France, Luxembourg and the southern part of Scandinavia. GenBank sequence PV 330055 also indicates its presence in Belgium. In turn, E. perflua seems to be restricted to more northern and eastern areas of Europe. Based on this distribution pattern, we treat E. quercina, originally collected in the north-eastern part of France, as a synonym of E. effusa . Maire (1902) stated that he had an opportunity to study authentic material of E. quercina stored in alcohol. The current location of this material is unknown. We therefore select a neotype for E. quercina .</p></div>	https://treatment.plazi.org/id/26560DEFADDF5E4DA51E9F4652B44F41	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
8370AF5C70F95202B7F92DAEF220BF46.text	8370AF5C70F95202B7F92DAEF220BF46.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis invasa Hauerslev	<div><p>Exidiopsis invasa Hauerslev, Mycotaxon 49: 221, 1993</p><p>Note.</p><p>Exidiopsis invasa was described as an intrahymenial parasite of Trechispora microspora (P. Karst.) Liberta ( Trechisporales) (Hauerslev 1993). Morphological traits (small basidia, subglobose basidiospores and the presence of haustorial cells) suggest that E. invasa is most likely a member of the Tremellomycetes . No modern collections of this species are known to us.</p></div>	https://treatment.plazi.org/id/8370AF5C70F95202B7F92DAEF220BF46	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
0CC5F046C2BA5CD28DC74789F1007F4D.text	0CC5F046C2BA5CD28DC74789F1007F4D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis perflua Spirin 2026	<div><p>Exidiopsis perflua Spirin sp. nov.</p><p>Figs 25 B, 27 B</p><p>Holotype.</p><p>Russia • Nizhny Novgorod Reg.: Lukoyanov Dist., <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=44.28289&amp;materialsCitation.latitude=54.92449" title="Search Plazi for locations around (long 44.28289/lat 54.92449)">Razino</a>, 54.92449; 44.28289, Ulmus glabra (fallen decorticated branch), 28 Jul 2021, Spirin 14386 * (H) .</p><p>Etymology.</p><p>Perfluus (Lat., adj.) – spilt, diffluent.</p><p>Description.</p><p>Basidiomata annual, effused, up to 15 cm in the longest dimension, waxy, up to 0.1 mm thick. Hymenial surface smooth, at first watery-grayish, semitranslucent, then often with pinkish or lilac hues, opaque, grayish-white in herbarium. Margin first pruinose, in older basidiomata rather sharply delimited or gradually thinning, adnate, concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae thin- or slightly thick-walled, interwoven or subparallel, anastomosing, 1.5–5 μm in diam., accidentally inflated up to 6–7 μm in diam., subhymenial hyphae thin-walled, interwoven or ascending, in older basidiomata partly agglutinated, 1.5–3 μm in diam.; basidia-bearing hyphae thin-walled, 2–4 (– 5) μm in diam. Hyphidia thin-walled, with a hyaline, hyphoid or nodulose stem, 2–6 μm in diam., and dendroid apical branches 0.5–1.5 μm in diam., scattered among basidia or partly covering hymenial cells and forming a continuous layer up to 20 μm thick. Probasidia broadly clavate, 13–29 × 5.5–14 μm. Basidia narrowly ellipsoid-ovoid to nearly obconical, four-celled, (10 –) 10.5–20 (– 21) × (6.6 –) 6.9–13.6 (– 15.8) μm (n = 101 / 9), thin-walled, exposed or embedded, occasionally with a distinctly tapering stalk-like base, up to 5 × 4 μm, sterigmata up to 45 × 2–3 μm. Basidiospores thin-walled, allantoid to cylindrical, more rarely broadly cylindrical, often distinctly curved, (9.8 –) 10.1–16.1 (– 17.6) × (3.8 –) 3.9–6.2 (– 6.4) μm (n = 300 / 10), L = 11.90–14.00, W = 4.11–5.83, Q = 2.05–3.24.</p><p>Remarks.</p><p>Exidiopsis perflua is introduced here as a sister species of E. effusa . Macroscopically, it can be differentiated from the latter species due to its smooth basidiomata which become opaque when mature or after drying. In contrast, basidiomata of E. effusa remain semitranslucent and they often bear small spine-like projections on the hymenial surface. Microscopically, E. perflua differs from E. effusa in having slightly narrower subhymenial hyphae and smaller basidia which are often openly arranged. These differences are subtle, however, and in many cases the basidiospore size does not separate the two species either. According to our data, the distribution areas of the two species do not coincide, at least at the large extent: Exidiopsis perflua appears to prefer colder areas with a more continental climate and E. effusa seems to be restricted to the western, more temperate parts of Europe</p><p>Exidiopsis perflua and E. effusa produce basidiomata from midwinter through the early summer. During colder seasons, they may persist longer, until July or August. Both species inhabit still hard, dead, hanging or just fallen branches or, more rarely, thin dead standing logs of angiosperms. These branches are usually partly covered by bark, and the basidiomata of Exidiopsis spp. occur on decorticated parts.</p></div>	https://treatment.plazi.org/id/0CC5F046C2BA5CD28DC74789F1007F4D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
A615A07C3C64507C812879A894679E8F.text	A615A07C3C64507C812879A894679E8F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis pulverea Hauerslev	<div><p>Exidiopsis pulverea Hauerslev, Mycotaxon 49: 225, 1993</p><p>Holotype.</p><p>Denmark • Midtjylland: Barrit, Stagsrode Skov, Cryptomeria japonica, 12 Oct 1963, Hauerslev 2209 (C 19750, studied) .</p><p>The species possesses gloeocystidia and basidia covered by involucres and should be therefore treated as a member of Basidiodendron s. lato. Its phylogenetic position is the subject of a forthcoming publication.</p></div>	https://treatment.plazi.org/id/A615A07C3C64507C812879A894679E8F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
682F7D58326D501C88CF81551AEDF4CF.text	682F7D58326D501C88CF81551AEDF4CF.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis tenuis Hauerslev	<div><p>Exidiopsis tenuis Hauerslev, Mycotaxon 49: 227, 1993</p><p>Holotype.</p><p>Denmark • Hovedstaden: Holte, on wood, 20 May 1984, Hauerslev 6323 (C 19749, studied) .</p><p>Morphological traits place E. tenuis in the vicinity of Basidiodendron radians (Rick) P. Roberts s. lato. The identity of E. tenuis will be clarified on another occasion.</p></div>	https://treatment.plazi.org/id/682F7D58326D501C88CF81551AEDF4CF	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
C03165B89CC35F50B1628683E17C1C90.text	C03165B89CC35F50B1628683E17C1C90.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Exidiopsis (Bref.) Vuillemin	<div><p>Exidiopsis (Bref.) Vuillemin, Bulletin des Séances de la Société des Sciences de Nancy 2 (3): 30, 1890</p><p>≡ Exidia subgen. Exidiopsis Bref., Untersuchungen aus dem Gesammtgebiete der Mykologie 7: 94, 1888.</p><p>Description.</p><p>Basidiomata annual, effused, waxy-gelatinous, watery-grayish, often with pink or lilac hues. Hymenial surface smooth or spinulose. Hyphal structure monomitic; hyphae clamped, hyaline, gelatinized and often agglutinated, basidia-bearing hyphae usually well-differentiated. Crystals rare or usually absent. Cystidia absent. Hyphidia present, not encrusted, at least partly covering basidial cells. Basidia four-celled, ellipsoid-ovoid, sessile, thin-walled, usually embedded, often with a distinct stalk-like base. Basidiospores thin-walled, cylindrical or allantoid, distinctly curved. On dead wood of angiosperms.</p><p>Generic type.</p><p>Exidia effusa Bref.</p><p>Our data show that the generic type of Exidiopsis, E. effusa, is not closely related to any other previously described Exidiopsis species. Instead, it is sister to Heteroradulum (Figs 1, 2; see Results) and, probably, Heterochaete s. typi (Malysheva and Spirin 2017); however, their phylogenetic relationships must be investigated further, with a much larger taxon sampling than used in the present study. In the current scope, the genus contains two species, E. effusa and E. perflua, introduced below. These two species differ from other species previously assigned to Exidiopsis in having pale and thin, waxy-gelatinous basidiomata, usually with a pink or lilac hue, ellipsoid-ovoid basidia with a clearly tapering base, long and curved basidiospores, as well as in lacking cystidia and distinctive encrustation.</p><p>The taxonomic history of the genus is complicated. Exidiopsis was first introduced by Brefeld (1888) as a subgenus of Exidia for a single species, Exidia effusa . However, the species name was given in his text as ‘ Exidiopsis effusa ’, and this naming became the source of subsequent controversy. Donk (1958) correctly cited Brefeld’s binomial as Exidia effusa and considered it as validly published. However, he changed his mind eight years later (Donk 1966) and cited Brefeld’s species as Exidiopsis effusa Bref. ‘ n. v. p. ’ (= not validly published). The reasons for this later interpretation were not provided. Most likely, Donk switched to a more literal interpretation of Brefeld’s description and considered Exidiopsis effusa as a new species described by Brefeld without introducing the appropriate genus for it, i. e. as invalid. This viewpoint was accepted by Index Fungorum and MycoBank (as of December 1 st, 2025), both listing Brefeld’s binomial as the invalidly published Exidiopsis effusa . However, Brefeld’s explanations in the protologue of Exidiopsis effusa clearly show that he found no grounds to raise Exidiopsis to the genus rank and even argued against this option (Brefeld 1888: 94–95). It is therefore evident that Brefeld ascribed his new species to Exidia and merely followed the fashion of the time in using subgenera along with generic names in the species descriptions. Hence, Exidia effusa .</p><p>Vuillemin (1890: 30) was the first author who used the name Exidiopsis at the genus level. He introduced a new species under the name Exidiopsis quercina and compared it with ‘ Exidiopsis effusa Bref. ’ By using the latter binomial, Vuillemin in fact created a new combination, Exidiopsis effusa (Bref.) Vuillemin, as was already noted by Donk (1958). Donk (ibid.) further stated that the new species E. quercina and the new combination E. effusa were not validly published by Vuillemin because he ‘ did not mention separately’ the generic name, i. e. Exidiopsis, at its new rank. However, this is not necessary under the current version of the Code: the indication ‘ Exidiopsis effusa Bref. ’ in Vuillemin’s description constitutes an indirect reference not only to Exidia effusa Bref. (Art. 38.14) but also to Exidiopsis as a validly published subgenus of Exidia (Art. 41.3). In other words, Vuillemin simultaneously combined Exidia effusa in Exidiopsis and raised the latter name to genus rank, thus fulfilling the requirements of Art. 41.2. Therefore, the generic name must be cited as Exidiopsis (Bref.) Vuillemin, while Exidiopsis (Bref.) Möller is merely its later isonym.</p></div>	https://treatment.plazi.org/id/C03165B89CC35F50B1628683E17C1C90	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
69224ECD783954D3B0BE081208793E51.text	69224ECD783954D3B0BE081208793E51.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Heterochaete mussooriensis Bodman	<div><p>Heterochaete mussooriensis Bodman, Lloydia 15: 221, 1952</p><p>Holotype.</p><p>India • Uttarakhand: Mussoorie, dead wood, 20 Jul 1940, Ahmad 375 (NY 00738345, studied) .</p><p>Li et al. (2023) combined H. mussooriensis from India in Heteroradulum and placed Heteroradulum semis Spirin &amp; Malysheva, recently described from East Asia (Malysheva and Spirin 2017), among its synonyms. However, they did not study the type specimen of H. mussooriensis and based their synonymy merely on reading the protologue. We did study the type of H. mussooriensis in 2016, before H. semis was introduced, and our study showed that these taxa are not conspecific. Heterochaete mussooriensis has pale, thin (up to 200 μm thick) basidiomata with adnate and rather poorly differentiated margin which are strongly different from the bright-colored, considerably thicker, partly detaching basidiomata of H. semis . Moreover, hymenial spines of H. mussooriensis are more sparsely arranged (4–5 per mm) than in H. semis (5–7 per mm). We could not find any ripe spores in the type specimen of H. moossoriensis although measurements given in the protologue (Bodman 1952), 12–15 × 9–10 μm, definitely preclude H. semis (basidiospores measured 11–14 × 6–7.5 μm). Nevertheless, morphological traits of H. mussooriensis point to Heteroradulum as the correct genus for it but its position therein should be re-assured with the use of DNA data.</p></div>	https://treatment.plazi.org/id/69224ECD783954D3B0BE081208793E51	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
BF3697B3AD6C530E8182A6DE6A5CFC26.text	BF3697B3AD6C530E8182A6DE6A5CFC26.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Heterochaete nigerrima Viegas	<div><p>Heterochaete nigerrima Viégas, Bragantia 5: 240, 1945</p><p>= Tremellochaete nigerrima (Viégas) Spirin &amp; Malysheva, Fungal Biology 121: 714, 2017.</p><p>Holotype.</p><p>Brazil • São Paulo: Campinas, Arraial dos Souzas, 22 Sep 1935, Krug 1157 (NY 00738346 – isotype, studied) .</p><p>This species shows a great similarity to Exidia japonica, the generic type of Tremellochaete, and it was therefore combined in that genus (Malysheva and Spirin 2017). No sequences of H. nigerrima have been available so far. Considering the existence of several competing names for Tremellochaete spp. from the tropics, we refrain from recombining H. nigerrima in Exidia until the species is connected to newly collected material and DNA data.</p></div>	https://treatment.plazi.org/id/BF3697B3AD6C530E8182A6DE6A5CFC26	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
2AE2B030B61C5255949F43361D513DED.text	2AE2B030B61C5255949F43361D513DED.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Leiostroma farinellum (P. Karst.) Spirin 2026	<div><p>Leiostroma farinellum (P. Karst.) Spirin comb. nov.</p><p>Figs 25 C, 27 C, 28</p><p>≡ Xerocarpus farinellus P. Karst., Bidrag till Kännedom av Finlands Natur och Folk 37: 139, 1882. Holotype. Finland. Etelä-Häme: Tammela, Mustiala, Picea abies, 4 Oct 1880, Karsten 1876 (H 6054654, studied) .</p><p>= Thelephora acerina var. abietis Fr., Systema Mycologicum 1: 453, 1821. Neotype (designated here, MBT 10031452). Sweden. Uppland: Stockholm, Picea abies, [no collecting date], Romell (# 129 in Fungi Exsiccati Praesertim Scandinavici) (S F 350638, studied) .</p><p>= Corticium abietis (Fr.) Romell, Botaniska Notiser: 72, 1895.</p><p>= Thelephora calcea Pers., Synopsis Methodica Fungorum 2: 581, 1801. Lectotype (selected here, MBT 10031453). [No locality or collecting date indicated], herb. Persoon (L 0054598, studied) .</p><p>= Sebacina calcea Bres., Fungi Tridentini 2: 64, 1892, pr. p.</p><p>= Exidiopsis calcea (Pers.) K. Wells, Mycologia 53: 348, 1961, pr. p.</p><p>Description.</p><p>Basidiomata annual, effused, up to 10 cm in the widest dimension, arid, soft, 0.1–0.5 mm thick. Hymenial surface smooth or indistinctly warted, at first nearly white, with grayish or brownish flecks, then ash- to mouse-gray, in older basidiomata brownish-gray, occasionally irregularly cracking. Margin at first arachnoid, then rather sharply delimited, adnate, as a rule remaining white, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, slightly to distinctly thick-walled, interwoven or subparallel, in older basidiomata partly agglutinated, 2–5 μm in diam., subhymenial hyphae hyaline or grayish-brownish, thin- to slightly thick-walled, ascending or interwoven, rather loosely arranged, occasionally twisted, 1.5–4 μm in diam., basidia-bearing hyphae thin- to slightly thick-walled, 3–5.5 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Amorphous, brownish, faintly CB (+) substance abundant in senescent hymenium, partly covering hymenial cells. Hyphidia thin- to slightly thick-walled, often in groups of 3–10, with a cystidium-like, narrowly clavate-subfusiform or hyphoid stem, 19–85 × 2–10 μm, occasionally with CB (+), refractive, brownish contents, often bearing several richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex; apical branches encrusted by small, densely arranged crystals. Basidia four-celled, broadly ellipsoid-ovoid to obconical, sessile, (14.5 –) 15–24 (– 25.5) × (8.8 –) 9.1–15.3 (– 15.6) μm (n = 60 / 5), thin-walled or with a distinct wall, embedded or exposed, sometimes with a short stalk-like base, up to 6 × 5 μm, sterigmata up to 35 × 3–3.5 μm; some basidia with a grayish-brownish cytoplasm. Basidiospores thin-walled, broadly to narrowly cylindrical, often distinctly curved, (10.2 –) 11.2–18.0 (– 18.1) × (4.5 –) 4.8–7.7 (– 7.8) μm (n = 210 / 7), L = 13.23–15.75, W = 5.33–6.67, Q = 2.37–2.91.</p><p>Remarks.</p><p>Leiostroma farinellum is widely distributed in the northern hemisphere and occurs almost exclusively on dead, often still corticated wood of conifers. We so far have only one verified collection of L. farinellum from an angiosperm host. In the central and southern parts of Europe, L. farinellum is clearly restricted to the mountain areas. ITS sequences of two Canadian collections show small differences from the sequences of L. farinellum from Europe and differences in TEF 1 region are even more substantial. However, we could not find any reliable morphological differences between the Eurasian and the North American specimens. Their identity deserves a closer look and the species name Sebacina monticola from Colorado (Burt 1915) should be kept in mind while revising the L. farinellum group in North America. Morphological differences between L. farinellum and the macroscopically similar Adustochaete hiemalis, Leiostroma incanum, L. infecundum, and Proterochaete letendreana are described in the remarks on these species.</p><p>Up to now, Leiostroma farinellum (at least its specimens from coniferous wood) was treated under the name Exidiopsis calcea . The latter combination made by Wells (1961) is based on Thelephora calcea Pers. (Persoon 1801). This name is, however, a homonym of the sanctioned T. calcea Fr. (Fries 1828), and it is thus unavailable (Code Art. 3.4). The identity of Fries’ T. calcea was discussed by Romell (1895), Litschauer (1938) and Rogers and Jackson (1943). They all univocally rejected its application to T. calcea Pers. sensu Bresadola (1898, as Sebacina calcea). We agree with their standpoint; the protologue of T. calcea Fr. in Elenchus clearly precludes T. calcea sensu Bres. and most likely refers to Resinicium furfuraceum (Bres.) Parmasto (= Skvortzovia furfuracea (Bres.) Gruhn &amp; Hallenberg, Hymenochaetales). By moving Persoon’s species to Sebacina, Bresadola (1898) made this name available for a heterobasidiomycete species discussed here. However, his Sebacina calcea is preceded by Xerocarpus farinellus P. Karst. (Karsten 1882) and Corticium abietis (Fr.) Romell (Romell 1895), and it has never been typified. We therefore choose X. farinellus to make a new combination in Leiostroma .</p><p>The identity of S. calcea (= E. calcea) was mixed in all older sources, and we see no advantage in saving Persoon’s name via conservation. Even in North Europe, S. calcea was in use for at least two species, L. farinellum and Tegmenticium peritrichum (Romell’s specimens from deciduous hosts cited by Romell 1895; Neuhoff 1936 b). Descriptions of the species by Bresadola (1898), Bourdot and Galzin (1927) and Malençon (1954) from the southern part of Europe and northern Africa were based on collections from both angiosperms and coniferous trees. In these geographic areas, they might have covered five morphologically similar species from four different genera, i. e. Adustochaete hiemalis, Leiostroma farinellum, L. incanum, Proterochaete letendreana, and Ulocolla corticioides . It is therefore difficult to argue in favor of conserving T. calcea Pers. as a well-known and widespread species.</p></div>	https://treatment.plazi.org/id/2AE2B030B61C5255949F43361D513DED	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
0170A89F61B45B0F9C7DE9D16E17A72C.text	0170A89F61B45B0F9C7DE9D16E17A72C.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Leiostroma Fr.	<div><p>Leiostroma Fr., Novitiae Florae Suecicae 5: 80, 1819</p><p>Description.</p><p>Basidiomata annual, effused, arid, soft and easily crumbling, nearly white to gray or brown. Hymenial surface smooth or spinulose. Hyphal structure monomitic; hyphae clamped, hyaline or grayish-brownish, normally spaced, basidia-bearing hyphae well-differentiated. Crystals abundant, angular or sand-like. Cystidia absent. Hyphidia present, with a well-differentiated, often widened stem and richly branched, densely encrusted apical outgrowths. Basidia four-celled, ellipsoid-ovoid to obconical, sessile, thin-walled or with a distinct wall, exposed or embedded, occasionally with a reduced stalk-like base; some basidia with a grayish-brownish cytoplasm. Basidiospores thin-walled, narrowly to broadly cylindrical, curved. On dead wood of angiosperms and conifers.</p><p>Generic type.</p><p>Thelephora acerina var. abietis Fr. (= Corticium abietis (Fr.) Romell) (see comments below).</p><p>As reintroduced here, Leiostroma encompasses four species having soft, easily crumbling, effused basidiomata with more or less pronounced tints of gray or brown. The same colouration is also characteristic for the contents of (at least some) hyphae and hymenial cells. All included species lack cystidia and possess very characteristic, abundant, hyaline, sand-like crystalline encrustation. These encrusting bodies are often very densely arranged, which makes microscopic structures difficult to observe. They form continuous shields on subicular hyphae and, in mature basidiomata, also on subhymenial hyphae and occasionally on hymenial cells (Fig. 28). These features, as well as the lack of cystidia, separate Leiostroma spp. from the similar-looking smooth Adustochaete species. Moreover, basidia-bearing hyphae are well differentiated in Leiostroma and usually clearly wider than subhymenial hyphae; in Adustochaete spp., no perceptible difference between these hyphal types was observed. Some Proterochaete spp. ( P. furfurosa, P. letendreana, and P. mucedinea) macroscopically similar to Leiostroma can be differentiated by their more densely arranged, partly glued hyphae (vs. spaced in the latter genus), as well as the presence of cystidia (except for P. letendreana) and granular, brownish, cyanophilous deposits on hyphae and hymenial cells. Differences between the two genera are discussed in more detail under Proterochaete . Mature, faded basidiomata of Tegmenticium peritrichum can be mistaken for Leiostroma spp.; however, it has cystidia and is devoid of incrustation on hyphae and hymenial cells.</p><p>Here we reinstate the generic name Leiostroma to encompass, to some extent, a species, formerly known as Exidiopsis calcea in North Europe, as well as three closely related species from the southern part of Europe, Macaronesia and Africa. Liu et al. (2022) uncritically took E. calcea and, without clarifying its identity, combined it in their newly described genus, Alloexidiopsis . The genus was typified with the simultaneously introduced A. schistacea, an effused, Heterochaete - like species from the southern part of China. The latter species is probably identical with Heterochaete cretacea Pat. from Vietnam (Patouillard 1924). Although it was shown by Liu et al. (2022) as forming a strongly supported clade with the so-called E. calcea and several other species, the question about their relationships, in our opinion, cannot be solved solely on the basis of the ribosomal gene-based phylogenies. Available ITS sequences of A. schistacea reveal a relatively low similarity (less than 94 %) with E. calcea s. auct. and three other species dealt with below. LSU sequences of this species provide no additional information because they show A. schistacea to be very close to and, at the same time, equally distant from E. calcea s. auct. with its closest relatives on one hand and Heteroradulum spp. on another (98.5–98.7 % similarity). Due to the lack of the specimens suitable for obtaining additional genetic markers, we leave the question about the phylogenetic placement of A. schistacea open. In the following paragraphs, we argue for resurrecting the genus name Leiostroma for E. calcea s. auct. and its closest relatives; our arguments in favor of discarding the species name Thelephora calcea Pers. (basionym of E. calcea) are provided under Leiostroma farinellum .</p><p>The genus Leiostroma was introduced by Fries (1819) without any species assigned to it (“ Species plures ”). Two years later, Fries (1821) lowered the rank of Leiostroma to the section in the genus Thelephora and described six species therein, i. e. Thelephora acerina, T. cinerea, T. fallax, T. maculaeformis, T. amphibolia, and T. sterilis . It seems this list reflects his original views on the scope of Leiostroma because the description of the section in Systema expands the earlier generic description of Leiostroma and does not contradict it. Donk (1957) treated Leiostroma sensu Fries 1821 as a subgenus of Thelephora and typified it with T. maculaeformis . He argued that T. maculaeformis was a ‘ constant member’ of Leiostroma, while two other candidates for typification, T. cinerea and T. acerina, had been subsequently removed by Fries himself and placed in other sections or genera. Later Donk (1963) detected that Leiostroma was published as a genus already in 1819; he, however, maintained his earlier typification of it with T. maculaeformis, providing no new arguments. The type material of T. maculaeformis was studied by Eriksson (1950) who found it to be conspecific with Peniophora polygonia (Pers.) Bourdot &amp; Galzin. The latter species is a member of Peniophora in the current sense (Hallenberg et al. 1996).</p><p>Before 1982, Donk’s typification looked harmless because Leiostroma was considered a devalidated name, i. e. that published prior to Fries’ Systema Mycologicum and therefore having no priority over generic names introduced afterwards. However, after changing the starting point for validly published fungal genera in 1982, Leiostroma becomes an older name for Peniophora, a large and widely accepted genus of crust fungi. This name change looks very unfortunate, and we therefore argue in favor of abandoning Donk’s typification and conserving Leiostroma with another generic type.</p><p>Under Code Art. 10.2, any of the six mentioned species mentioned by Fries (1821) is suitable for lectotypification of the genus. However, the first five species are currently classified among well-established genera of corticioid fungi, i. e. Dendrothele Höhn. &amp; Litsch. ( T. acerina), Peniophora Cooke ( T. cinerea, T. fallax, and the already mentioned T. maculaeformis), and Phanerochaete P. Karst. ( T. amphibolia). Selecting any of these species as a lectotype of Leiostroma would result in discarding one of these currently accepted corticioid genera ( Dendrothele, Peniophora, or Phanerochaete) from use because it is older than any of them. As far as we know, no authentic specimens of the sixth species, Thelephora sterilis, exist.</p><p>In the subsequent reintroduction of the section Leiostroma, Fries (1828: 224) retained four species from the previous treatise ( T. acerina, T. maculaeformis, T. amphibolia, and T. sterilis) and added seven more species, i. e. T. corrugata, T. laevigata, T. episphaeria, T. bufonia, T. circinata, T. typhae, and T. epiphylla . Again, choosing any of these species as the generic type of Leiostroma is problematic: T. corrugata and T. episphaeria are currently treated under Hydnoporia, T. laevigata is a species of Amylostereum, T. circinata is the generic type of Sarcopodium (Ascomycota), T. typhae is the generic type of Epithele, and T. epiphylla is that of Athelia . All these currently accepted generic names (except Athelia and Sarcopodium) are younger than Leiostroma . As for T. bufonia, its identity remains uncertain. There are five specimens in Persoon’s herbarium in Leiden identified as T. bufonia, representing various bark-inhabiting fungi. It seems that Fries was uncertain about identity of this species, and it was certainly not the source of his concept of Leiostroma . This leads us to a conclusion that there are no species associated with Leiostroma which could be suitable for the typification of this genus without causing problems for the current classification of fungi. Therefore, we have to return to the original description of the genus by Fries in 1819.</p><p>The Code Art. 10.2 provides us with a choice: either to select a lectotype of Leiostroma among the species associated with its later reintroduction as a section in the genus Thelephora, or to choose the type otherwise. The first option looks inconvenient because – as we demonstrated above – it would lead to a disposal of the currently accepted and well-defined genera. So, we follow the second option aligning it, as much as possible, with Fries’ concept of Leiostroma as he developed between 1819 and 1828. In both Systema and Elenchus, Fries listed Thelephora acerina as the first species in the section Leiostroma . He most likely viewed it as the most “ typical ” representative of the section because the most important features of its introduction (basidiome shape and consistency, hymenium configuration) in Systema repeat those in the section’s description. The species was introduced with four varieties, of which the first, T. acerina var. abietis, is of special interest for the present study. It certainly refers to a taxon macroscopically similar to Dendrothele acerina but occurring on Picea and clearly implies a widely distributed conifer-dwelling species which was treated as Sebacina or Exidiopsis calcea after Bresadola (1898) and Wells (1961). In our opinion, the latter name is inapplicable to T. acerina var. abietis (see remarks under Leiostroma farinellum) and must be interpreted otherwise. Romell (1895) was the first who clarified the identity of var. abietis, and we see no reasons to reject his interpretation. He raised it to the species level; however, his Corticium abietis is preceded by Xerocarpus farinellus by Karsten (1882) which we reinstate as a species of Leiostroma below. Nevertheless, this fact does not make T. acerina var. abietis unsuitable for the typification of the genus. We therefore propose to conserve it as a type of Leiostroma . A conservation proposal has been submitted to the Nomenclatural Committee for Fungi.</p></div>	https://treatment.plazi.org/id/0170A89F61B45B0F9C7DE9D16E17A72C	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
ADE2A655E6055883BD47DEC8DA24F19A.text	ADE2A655E6055883BD47DEC8DA24F19A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Leiostroma incanum Spirin & Viner 2026	<div><p>Leiostroma incanum Spirin &amp; Viner sp. nov.</p><p>Figs 25 D, 27 D</p><p>Holotype.</p><p>France • Alpes-Maritimes: Nice, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=7.30098&amp;materialsCitation.latitude=43.69971" title="Search Plazi for locations around (long 7.30098/lat 43.69971)">Mont Boron</a>, 43.69971; 7.30098, dead angiosperm branch, 17 Apr 2019, Viner 2019 / 280 * (H) .</p><p>Etymology.</p><p>Incanus (Lat., adj.) – whitened, faded.</p><p>Description.</p><p>Basidiomata annual, effused, up to 15 cm in the longest dimension, arid, soft, 0.1–0.3 mm thick. Hymenial surface smooth or indistinctly warted, grayish to mouse-gray, in older basidiomata brownish-gray or more rarely brown, occasionally minutely cracking (fissures seen with a lens only). Margin at first pruinose, then rather sharply delimited, adnate, white to grayish, up to 1 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, thin- to slightly thick-walled, interwoven or subparallel, occasionally glued in large bundles, 2–4 μm in diam., subhymenial hyphae hyaline or grayish-brownish, thin- to slightly thick-walled, ascending or interwoven, spaced or rather tightly arranged, occasionally twisted, 2–5 μm in diam., basidia-bearing hyphae thin- to slightly thick-walled, 2.5–5 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Amorphous, brownish, faintly CB (+) substance abundant in senescent hymenium, partly covering hymenial cells. Hyphidia thin- to slightly thick-walled, often in groups of 3–7, with a cystidium-like, clavate-subfusiform or hyphoid stem, 22–44 × 3–11 μm, occasionally with CB (+), refractive, brownish contents, often bearing several richly branched apical outgrowths, 0.8–1.5 μm in diam. at the very apex; apical branches usually encrusted by small, densely arranged crystals. Basidia four-celled, ellipsoid-ovoid to obconical, sessile, (14.5 –) 16–22 (– 22.5) × (9.2 –) 9.4–12.2 (– 12.9) μm (n = 40 / 4), thin-walled or with a distinct wall, embedded or exposed, sometimes with a short stalk-like base, up to 5 × 5 μm, sterigmata up to 35 × 3–5 μm; some basidia with a grayish-brownish cytoplasm. Basidiospores thin-walled, broadly cylindrical to cylindrical, more or less clearly curved, (9.3 –) 9.4–15.0 (– 15.3) × (4.9 –) 5.0–7.1 (– 7.3) μm (n = 150 / 5), L = 11.28–12.83, W = 5.70–6.30, Q = 1.93–2.16.</p><p>Remarks.</p><p>Leiostroma incanum is a sister species of L. farinellum . It is distributed in South Europe and the Caucasus and restricted to angiosperm hosts. Macroscopically, it differs from L. farinellum in having deeper-colored, often densely cracking basidiomata. Microscopically, the two species can be differentiated primarily by the basidiospore length: spores of L. incanum are on average shorter than in L. farinellum . The species also have different ecological preferences: L. farinellum is a boreal – alpine species while L. incanum clearly prefers areas with a Mediterranean climate. Another species macroscopically similar to L. incanum and often occurring in the same habitats is Proterochaete letendreana . Their differences are listed under the latter species. See also notes to L. infecundum and Ulocolla corticioides .</p><p>Our data indicate the presence of yet another Leiostroma species on angiosperm hosts in the Mediterranean (see Suppl. material 4, Fig. 5, as Leiostroma sp. 2). It is so far known from a single specimen from Toulon, France. Based on one collection, it is difficult to judge about morphological differences between this taxon and L. incanum . Therefore, we are unwilling to formally introduce it in the present paper awaiting a denser sampling of Leiostroma spp. in the southern part of Europe and northern Africa.</p></div>	https://treatment.plazi.org/id/ADE2A655E6055883BD47DEC8DA24F19A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
69007F3F317655FA90B506D09EDF72F0.text	69007F3F317655FA90B506D09EDF72F0.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Leiostroma infecundum Viner & Spirin 2026	<div><p>Leiostroma infecundum Viner &amp; Spirin sp. nov.</p><p>Figs 25 E, 27 E</p><p>Holotype.</p><p>Spain • Canary Ids.: La Palma, San Miguel de La Palma, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-17.78034&amp;materialsCitation.latitude=28.76032" title="Search Plazi for locations around (long -17.78034/lat 28.76032)">Puntallana, laurel forest</a>, 28.76032; – 17.78034, angiosperm wood, 30 Jul 2022, Viner 2022 / 1091 A * (H) .</p><p>Etymology.</p><p>Infecundus (Lat., adj.) – fruitless, infecund.</p><p>Description.</p><p>Basidiomata annual, effused, up to 5 cm in the longest dimension, arid, soft, 0.05–0.2 mm thick. Hymenial surface smooth, grayish to cream-colored, occasionally with poorly visible brownish flecks, in older basidiomata sometimes fading to almost white. Margin at first pruinose, then sharply delimited, adnate, concolourous with or slightly paler than hymenial surface, up to 1 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, with a distinct wall or slightly thick-walled, interwoven or subparallel, anastomosing, 2–5 μm in diam., subhymenial hyphae hyaline or more rarely grayish-brownish, thin- to slightly thick-walled, predominantly interwoven, anastomosing, spaced, occasionally twisted, 1–3.5 μm in diam., basidia-bearing hyphae with a distinct wall, 3–5 μm in diam. Crystals usually abundant in all parts of basidiomata, often encrusting hyphae and hymenial cells, small, angular to sand-like. Hyphidia thin- to slightly thick-walled, with cystidia-like, fusiform or hyphoid stem, 22–48 × 3–7.5 μm, bearing several richly branched apical outgrowths, 0.8–1.5 μm in diam. at the very apex; apical branches usually encrusted by small, densely arranged crystals. Basidia four-celled, ellipsoid-ovoid to obconical, sessile, (12 –) 12.5–22.5 (– 23) × (8.1 –) 8.6–12.1 (– 12.2) μm (n = 50 / 5), often with a distinct wall, usually embedded, sometimes with a short stalk-like base, up to 3 × 3 μm, sterigmata up to 35 × 3–5 μm; some basidia with a grayish-brownish cytoplasm. Basidiospores thin-walled, broadly to narrowly cylindrical, often more or less clearly curved, (9.5 –) 9.8–15.8 × (4.7 –) 4.8–6.6 (– 6.9) μm (n = 115 / 5), L = 10.58–13.60, W = 5.08–6.02, Q = 1.84–2.27.</p><p>Remarks.</p><p>Leiostroma infecundum is a look-alike of L. incanum distributed in Macaronesia. The basidiomata of L. infecundum are in general paler, devoid of deep gray tints, and as a rule thinner than those of L. incanum . Hyphidia of L. infecundum are narrower and more regular in shape than in L. incanum . Additionally, the two species can be distinguished due to different distribution areas and via DNA sequences. Most collections of L. infecundum studied by us are sterile.</p></div>	https://treatment.plazi.org/id/69007F3F317655FA90B506D09EDF72F0	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
A6C281944F6F506CB3962F9814D3F784.text	A6C281944F6F506CB3962F9814D3F784.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Leiostroma squalidum Spirin & A. Savchenko 2026	<div><p>Leiostroma squalidum Spirin &amp; A. Savchenko sp. nov.</p><p>Fig. 27 F</p><p>Holotype.</p><p>Kenya • Taita-Taveta: Taita Hills, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=38.34067&amp;materialsCitation.latitude=-3.37043" title="Search Plazi for locations around (long 38.34067/lat -3.37043)">Ngangao Forest</a>, – 3.37043; 38.34067, corticated angiosperm branch, 24 Nov 2017, Savchenko 171124 / 1010 * (H 7008778, isotype – EA) .</p><p>Etymology.</p><p>Squalidus (Lat., adj.) – rough, shaggy.</p><p>Description.</p><p>Basidiomata annual, effused, up to 15 cm in the longest dimension, arid, rather soft, 0.1–0.2 mm thick. Hymenial surface spinulose, cream-colored to gray or brownish-gray, spines rather regularly distributed, sharp-pointed, 100–200 × 30–60 μm, 6–9 per mm. Margin at first pruinose, then rather abruptly delimited, adnate, white to cream-colored, up to 1 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or brownish, variably thick-walled, interwoven or subparallel, often agglutinated, 1.5–4 μm in diam., subhymenial hyphae hyaline or brownish, thin- to slightly thick-walled, interwoven, rather densely arranged, in older parts occasionally agglutinated, 1.5–3.5 μm in diam., basidia-bearing hyphae thin- to slightly thick-walled, 3–5 μm in diam. hyphae of hymenial spines hyaline or brownish, slightly to distinctly thick-walled, ascending, often agglutinated, in older parts cemented by amorphous brownish substance, CB (+), 1.5–4 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular to sand-like. Hyphidia thin- to slightly thick-walled, single or in groups of 3–5, with narrowly clavate, subfusiform or hyphoid stem, 19–42 × 3–5 μm, bearing numerous richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex; apical branches encrusted by small, densely arranged crystals. Basidia four-celled, narrowly ellipsoid-ovoid to obconical, sessile, (15 –) 15.5–22 (– 24) × (8.2 –) 9.1–12.6 (– 12.8) μm (n = 35 / 3), thin-walled or with a distinct wall, embedded or exposed, occasionally with reduced stalk-like base, up to 8 × 4.5 μm, sterigmata up to 30 × 3–4 μm, some basidia with a grayish-brownish cytoplasm. Basidiospores thin-walled, broadly cylindrical to cylindrical, clearly curved, (9.0 –) 9.2–16.2 (– 16.5) × (4.3 –) 4.8–6.9 (– 7.1) μm (n = 90 / 3), L = 11.47–14.26, W = 5.21–6.18, Q = 2.16–2.31.</p><p>Remarks.</p><p>Leiostroma squalidum is the only representative of the genus having a spinulose (i. e. Heterochaete - like) hymenophore. Otherwise, it is morphologically very close to L. incanum and L. infecundum described above. Leiostroma squalidum seems to be widely distributed in East Africa because its occurrence has been currently confirmed in both Kenya and Zimbabwe.</p></div>	https://treatment.plazi.org/id/A6C281944F6F506CB3962F9814D3F784	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
E3F159EAE3BE50C4BBE6B730821F636E.text	E3F159EAE3BE50C4BBE6B730821F636E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Myxarium corticale Savchenko, Spirin & Malysheva 2026	<div><p>Myxarium corticale Savchenko, Spirin &amp; Malysheva sp. nov.</p><p>Holotype.</p><p>Norway • Akershus: Ås, Ved Høyskolen, Populus tremula (fallen corticated branch), 10 Dec 1972, Hansen &amp; Gulden 595 / 72 * (O F 160494) .</p><p>Etymology.</p><p>Corticalis (Lat., adj.) – bark-inhabiting, in reference to the occurrence on corticated tree branches.</p><p>Description.</p><p>Basidiomata annual, gelatinous, first semitranslucent, pustulate, about 1 mm in diam., then fusing together, cerebriform or adpressed-orbicular, finally opalescent or opaque, up to 8 mm in the widest dimension and 1–5 mm thick. Hymenial surface hyaline, often with light yellowish or brownish tints, then almost white, indistinctly furrowed to more or less smooth, in herbarium specimens pale ochraceous or brownish. Mineral inclusions usually absent or, if present, very small, embedded in hymenial layer and seen only under magnification. Margin detaching, later adnate, compact, more or less concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped (clamps often open); context hyphae hyaline, predominantly interwoven, thin-walled or with a distinct wall, 3–6 μm in diam., often clearly swollen at septa and then up to 9 μm in diam., subhymenial hyphae hyaline, thin-walled, mostly ascending, 1–2.5 μm in diam. Cystidia absent. Hyphidia richly branched, thin-walled, hyaline, apical branches 1–2 μm in diam., covering hymenial surface. Basidia four-celled, ellipsoid-ovoid to subglobose, 11–17.5 × 7–13 μm, with a well-pronounced basal enucleate stalk up to 65 × 3.5 μm. Basidiospores thin-walled, narrowly to broadly cylindrical, slightly to distinctly curved, (8.6 –) 8.9–14.0 (– 14.5) × (3.4 –) 3.5–5.7 (– 5.8) μm (n = 180 / 6), L = 10.20–12.21, W = 4.15–5.01, Q = 2.38–2.64.</p><p>Remarks.</p><p>Myxarium corticale was illustrated as M. cinnamomescens in Spirin et al. (2018, 2019). All specimens named as M. cinnamomescens in the latter two papers (except for the type of E. cinnamomescens), as well as in Põldmaa et al. (2019) and Spirin et al. (2025), belong to M. corticale . Phylogenetically, M. corticale is a sister species of M. populinum . In most cases, they can be differentiated due to their host preference: M. populinum seems to be restricted to Populus tremula, with a few records on Salix spp., while M. corticale occurs on different angiosperm hosts, most often on Betula, Fraxinus, Padus, and Tilia . However, it may inhabit P. tremula, too. Only the aspen-dwelling specimens with an average spore width exceeding 4.8 μm can be safely identified as M. corticale and those ones with an average spore width less than 4.1 μm as M. populinum . With our current knowledge, morphological recognition is more or less impossible for the specimens on aspen with the average spore width falling between 4.1 and 4.8 μm. In these cases, M. corticale and M. populinum can be differentiated exclusively via ITS sequencing.</p></div>	https://treatment.plazi.org/id/E3F159EAE3BE50C4BBE6B730821F636E	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
C5C6998461145A2EB3E71A97C1B72A96.text	C5C6998461145A2EB3E71A97C1B72A96.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pholiobasidion senex Spirin & Grootmyers 2026	<div><p>Pholiobasidion senex Spirin &amp; Grootmyers sp. nov.</p><p>Figs 25 F, 29</p><p>Holotype.</p><p>USA. Ohio: Licking Co., <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=82.571&amp;materialsCitation.latitude=40.0641" title="Search Plazi for locations around (long 82.571/lat 40.0641)">Alexandria, 4235 Morse Rd.</a>, 40.0641; 82.5710, strongly decayed angiosperm log, 6 Oct 2019, Grootmyers (H *, isotype – TENN) .</p><p>Etymology.</p><p>Senex (Lat., adj.) – ancient, old; in reference to grayish color of basidiomata.</p><p>Description.</p><p>Basidiomata annual, effused, at first appearing as small (up to 0.5 mm in diam.) adpressed-pustular bodies, then fusing together and forming a compound basidiome, up to 2 cm in widest dimension, gelatinous, 0.1–0.2 mm thick, opaque, smooth or tuberculate, watery-grayish, drying to a grayish crust. Margin poorly differentiated, gradually thinning, adnate.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, with a distinct wall, predominantly subparallel, anastomosing, 1.5–2.5 (3) μm in diam., subhymenial hyphae hyaline, thin-walled, ascending or interwoven, sometimes embedded in gelatinous matrix, 1–2 μm in diam., basidia-bearing hyphae poorly differentiated, hyaline, thin-walled, 1–1.5 μm in diam. Cystidia abundant, hyaline, thin-walled, tapering-clavate, embedded or slightly projecting, 11–25 × 5–7.5 μm. Hyphidia rare, simple or sparsely branched, 1–1.5 μm in diam., scattered among basidia. Basidia four-celled, broadly ellipsoid to subglobose, sessile, (7.3 –) 7.8–9.4 (– 10.2) × (6.2 –) 6.8–8.2 (– 8.6) μm (n = 20 / 1), thin-walled, often glued in groups of up to four and covered by shields of hyphidia and remnants of collapsed basidia, sterigmata up to 5 × 1.5–2 μm. Basidiospores thin-walled, broadly cylindrical to broadly ellipsoid, (5.1 –) 5.2–7.1 (– 7.2) × (3.3 –) 3.5–4.4 (– 4.6) μm (n = 30 / 1), L = 6.18, W = 4.12, Q = 1.51.</p><p>Remarks.</p><p>Pholiobasidion senex is the only known species of the genus. It has so far only been found in the type locality in Ohio, USA, where it inhabited a strongly rotten angiosperm log. The differences of P. senex from the superficially similar Basidiodendron spp. are listed above.</p></div>	https://treatment.plazi.org/id/C5C6998461145A2EB3E71A97C1B72A96	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
20257706F16F50EA8B9A63C0F4C5CFF3.text	20257706F16F50EA8B9A63C0F4C5CFF3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pholiobasidion Spirin & Grootmyers 2026	<div><p>Pholiobasidion Spirin &amp; Grootmyers gen. nov.</p><p>Etymology.</p><p>Derived from ‘pholia’ (Greek, noun) – a nest, and ‘basidium’.</p><p>Description.</p><p>Basidiomata annual, effused, gelatinous, opaque, smooth or tuberculate, watery-grayish, margin gradually thinning, adnate. Hyphal structure monomitic, hyphae clamped, hyaline; basidia-bearing hyphae poorly differentiated. Cystidia abundant, hyaline, thin-walled, tapering-clavate. Hyphidia rare, simple or sparsely branched. Basidia four-celled, broadly ellipsoid to subglobose, sessile, thin-walled, often glued in groups of up to four and covered by shields of hyphidia and remnants of collapsed basidia. Basidiospores hyaline, thin-walled, broadly cylindrical to broadly ellipsoid, repetitive, apiculus small. On dead wood of angiosperms.</p><p>Generic type.</p><p>Pholiobasidion senex .</p><p>Our data show that Pholiobasidion is sister to the rest of the Auriculariaceae (Figs 1, 2). Whether it belongs to the family or should be treated separately from the Auriculariaceae is a question which cannot be solved without a much denser sampling among the residual Auriculariales . Morphologically, Pholiobasidion is strikingly similar to Basidiodendron spp. due to its small, broadly ellipsoid or subglobose basidia grouped together and covered by remnants of collapsed hymenial cells. However, the remaining morphological traits point elsewhere. In particular, there are no differentiated fishbone-like basidia-bearing hyphae in Pholiobasidion which are so characteristic of the core Basidiodendron spp. Moreover, cystidia of P. senex lack oily, strongly cyanophilous contents and should thus be considered as normal cystidia. In contrast, all species of Basidiodendron possess easily detectable gloeocystidia. Basidiospores of Pholiobasidion have a conventionally located, rather small and symmetric apiculus (Fig. 29) – they therefore look quite different from the spores of Basidiodendron (cf. Spirin et al. 2020, 2021). Phylogenetically, the core Basidiodendron spp. are related to Protohydnum and form a clade which is very distant from the Auriculariaceae (Spirin et al. 2025) .</p></div>	https://treatment.plazi.org/id/20257706F16F50EA8B9A63C0F4C5CFF3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
43BF5EAEF8DB5A01A59AD51ED2CCBDB8.text	43BF5EAEF8DB5A01A59AD51ED2CCBDB8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete abstrusa Spirin 2026	<div><p>Proterochaete abstrusa Spirin sp. nov.</p><p>Figs 31, 32 A</p><p>Holotype.</p><p>Italy • Liguria: Imperia, Pigna, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=7.688&amp;materialsCitation.latitude=43.9625" title="Search Plazi for locations around (long 7.688/lat 43.9625)">Buggio</a>, 43.9625; 7.6880, Carpinus betulus (fallen, partly corticated branch), 17 Oct 2019, Spirin 13834 * (H) .</p><p>Etymology.</p><p>Abstrusus (Lat., adj.) – secret, hidden.</p><p>Description.</p><p>Basidiomata annual, effused, a few mm in diam., sometimes fusing together but rarely exceeding 1 cm in the widest dimension, at first waxy, then at least partly gelatinized, 0.05–0.1 mm thick, drying to a whitish or grayish, occasionally cracking shining crust. Hymenial surface at first opalescent, smooth, watery-grayish, then whitish, semitranslucent. Margin gradually thinning, adnate, first whitish, in older basidiomata concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped, clamps often ansiform; subicular hyphae hyaline, thin-walled, subparallel, anastomosing, 1.5–4 (5) μm in diam., occasionally irregularly inflated (up to 9 μm in diam.), subhymenial hyphae hyaline, thin-walled, predominantly ascending, 1.5–4 μm in diam., rarely inflated and then reaching 5–7 μm in diam., easily collapsing, basidia-bearing hyphae well-differentiated, hyaline, thin-walled, 2–5.5 μm in diam., sometimes showing a zigzag-like branching pattern. Crystals occasionally present as large, rosette-like agglomerations in subhymenium, up to 25 μm in diam. Cystidia usually absent; if present, then thin-walled, narrowly clavate or tapering, embedded or projecting, 21–63 × 5–11.5 μm, occasionally bearing 1–3 inner septa. Hyphidia hyaline, richly branched, with a long hyphoid or narrowly clavate stem, 2–6 μm, and hyaline apical branches, 1–2 μm in diam., covering basidia and occasionally forming a continuous layer up to 15 μm thick. Probasidia narrowly to broadly clavate, more rarely tapering, 11–24 × 4–10 μm. Basidia four-celled, ellipsoid-ovoid or pyriform to subglobose, sometimes obliquely septate, sessile, (13 –) 13.5–20.5 (– 21.5) × (9.2 –) 10.0–15.2 (– 15.9) μm (n = 90 / 9), thin- or slightly thick-walled, predominantly embedded, occasionally with a tapering stalk-like base, up to 10 × 4.5 μm, sterigmata up to 35 × 2.5–4.5 μm. Basidiospores thin-walled, cylindrical to broadly cylindrical, curved, more rarely subfusiform, some spores slightly constricted at the middle and somewhat swollen at the apex, (11.1 –) 11.3–23.8 (– 24.2) × (4.8 –) 4.9–9.1 (– 9.2) μm (n = 278 / 9), L = 13.77–18.99, W = 5.52–7.38, Q = 2.02–2.72.</p><p>Remarks.</p><p>Proterochaete abstrusa is a European species occurring in temperate forests on various plant remnants, normally on fallen but still corticated tree branches. One specimen was collected from a dead grass stem. The species produces thin, hygroscopic basidiomata which become almost invisible when dry. This feature, as well as the absence of regular crystalline encrustation on hyphae and the presence of well-differentiated basidia-bearing hyphae make P. abstrusa a somewhat deviating representative of the genus. Morphologically, it is most similar to the North American P. paniculata (see description below). However, the latter species produces thicker, tougher, and as a rule darker basidiomata. Moreover, hyphae of P. paniculata often bear angular crystals and it has larger basidia. Hyphidia of P. paniculata have a sinuous, often irregularly inflated stem; in contrast, hyphidial stems of P. abstrusa are often poorly differentiated from the surrounding hyphae (“ hyphoid ”). Cystidia were totally lacking in all but three specimens of P. abstrusa studied by us. In those three specimens, they are abundant and easily observable, varying from narrowly clavate to distinctly tapering.</p><p>Senescent, partly gelatinized basidiomata of P. abstrusa can be mistaken for the resupinate Exidia species, i. e. E. delita and E. plumbescens . However, these species possess thicker basidiomata than P. abstrusa; their hymenial surface is as a rule tuberculate and whitish mineral inclusions are often present. Additionally, E. plumbescens can be differentiated from P. abstrusa due to visibly swollen, subfusiform stems of the hyphidia. Hyphidia of E. delita are rather poorly differentiated, like in P. abstrusa, but its basidiospores are slightly shorter and clearly narrower than in the latter species. It should be noted, however, that the size of the basidiospores is exceptionally variable in P. abstrusa and cannot be used as the single trait to distinguish between it and similar species.</p></div>	https://treatment.plazi.org/id/43BF5EAEF8DB5A01A59AD51ED2CCBDB8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
2035B2F1083B509AA812CBA771228AF8.text	2035B2F1083B509AA812CBA771228AF8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete adusta (Burt) Spirin & Malysheva	<div><p>Proterochaete adusta (Burt) Spirin &amp; Malysheva, Botany 97: 447, 2019</p><p>≡ Sebacina adusta Burt, Annals of the Missouri Botanical Garden 2: 764, 1915. Lectotype (selected by Alvarenga et al. 2019: 447). USA. Idaho: Coolin, Populus trichocarpa, Sep 1915, Weir 3118 (BPI 723685, studied) .</p><p>For a description and further synonyms, see Alvarenga et al. (2019). Rödel et al. (2020) published excellent macro- and microphotographs of P. adusta .</p></div>	https://treatment.plazi.org/id/2035B2F1083B509AA812CBA771228AF8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
9C2AD4D7F6CB554E9AA7CBFB6BD3B710.text	9C2AD4D7F6CB554E9AA7CBFB6BD3B710.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete africana Spirin & Ryvarden 2026	<div><p>Proterochaete africana Spirin &amp; Ryvarden sp. nov.</p><p>Fig. 32 B</p><p>Holotype.</p><p>Uganda • Kabarole: Kibale National Park, Makere University Field Station, fallen corticated branch, 20 Apr 2002, Ryvarden 44921 * (O, isotype – H) .</p><p>Etymology.</p><p>Africanus (Lat., adj.) – African.</p><p>Description.</p><p>Basidiomata annual, effused, up to 3 cm in the longest dimension, arid, soft, 0.05–0.1 mm thick. Hymenial surface smooth or indistinctly tuberculate, at first pale ochraceous, then changing to ochraceous-grayish, in older basidiomata irregularly cracking and occasionally covered by dark reddish-brown dots. Margin at first floccose or nearly fibrillose, gradually thinning, whitish, then sharply delimited, compact, adnate, concolourous with hymenial surface, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, slightly-walled, subparallel, anastomosing, 2–3.5 μm in diam., subhymenial hyphae hyaline, thin- to slightly thick-walled, predominantly interwoven, 1.2–3 μm in diam., basidia-bearing hyphae poorly differentiated, with a distinct wall, 1.8–2.5 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, as a rule small, angular; amorphous brownish or rusty-brown, CB (+) concretions present, especially abundant in senescent parts. Needle-like crystals appearing in CB-mounted microscopic slides after 2–3 hours. Cystidia absent. Hyphidia with a thin- to slightly thick-walled, hyaline or rusty-brown, variably shaped (subfusiform, hyphoid or narrowly clavate) stem, 23–48 × 4–10 μm, often with a refractive, CB + content, bearing several richly branched, hyaline apical outgrowths, 0.8–1.2 μm in diam. at the very apex, partly covering basidia; apical branches usually encrusted by small, densely arranged crystals and occasionally bearing brownish amorphous grains. Basidia four-celled, obconical or more rarely ellipsoid-ovoid, sessile, (16.5 –) 17–25.5 (– 26) × (9.2 –) 9.4–11.8 (– 12.0) μm (n = 20 / 1), thin-walled or with a distinct wall, exposed or partly embedded, rarely with a short stalk, up to 3 × 3 μm, sterigmata up to 20 × 3–3.5 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, usually distinctly curved, longest spores rarely sigmoid, (11.7 –) 12.0–15.2 (– 15.3) × (5.2 –) 5.3–6.8 (– 6.9) μm (n = 30 / 1), L = 13.55, W = 6.08, Q = 2.23.</p><p>Remarks.</p><p>Proterochaete africana is one of two Proterochaete species so far detected in Africa. It is morphologically similar to P. furfurosa, described below. The two species can be separated by the presence of cystidia (lacking in P. africana, present in P. furfurosa), as well as the size of basidia and basidiospores (distinctly larger in P. africana than in P. furfurosa). Proterochaete africana is known so far only from the type locality in Uganda.</p></div>	https://treatment.plazi.org/id/9C2AD4D7F6CB554E9AA7CBFB6BD3B710	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
B8136071B9B95CE0AE137A95F07A2277.text	B8136071B9B95CE0AE137A95F07A2277.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete bambusicola (S. H. He, T. Nie & Yue Li) Spirin 2026	<div><p>Proterochaete bambusicola (S. H. He, T. Nie &amp; Yue Li) Spirin comb. nov.</p><p>≡ Heterocorticium bambusicola S. H. He, T. Nie &amp; Yue Li, Journal of Fungi 9 (3, 318): 7, 2023. Holotype. China. Jiangxi: Yifeng, Guanshan Nat. Reserve, culm of dead bamboo, 10 Aug 2016, He 4236 * (BJFC 023678) .</p><p>Note.</p><p>This species was introduced by Li et al. (2023) based on specimens from China and Malaysia. It is the generic type of Heterocorticium . Morphologically, H. bambusicola is most similar to Proterochaete stipidosa introduced below. However, it can be distinguished from the latter species by its longer basidiospores and the lack of cystidia. DNA sequences show that H. bambusicola and P. stipidosa are not closely related (Figs 3, 4) although they both belong to the redefined Proterochaete . We therefore combine H. bambusicola in Proterochaete .</p></div>	https://treatment.plazi.org/id/B8136071B9B95CE0AE137A95F07A2277	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
B5A14CA17EA15683B28DC87D067001E8.text	B5A14CA17EA15683B28DC87D067001E8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete furfurosa Spirin & Viner 2026	<div><p>Proterochaete furfurosa Spirin &amp; Viner sp. nov.</p><p>Fig. 32 C</p><p>Holotype.</p><p>Uganda • Kabarole: Kibale National Park, Makere University Field Station, fallen corticated branch, 20 Apr 2002, Ryvarden 44895 * (O, isotype – H) .</p><p>Etymology.</p><p>Furfurosus (Lat., adj.) – bran-like.</p><p>Description.</p><p>Basidiomata annual, effused, up to 5 cm in the longest dimension, waxy to arid, soft, 0.05–0.1 mm thick. Hymenial surface smooth, at first pale ochraceous, then changing to hazel-colored, in older basidiomata irregularly cracking and dark grayish-brown. Margin at first fibrillose, gradually thinning, whitish, then sharply delimited, cream-colored to grayish-brown, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or rarely brownish, slightly to distinctly thick-walled, subparallel or interwoven, anastomosing, often covered by crystalline shields, 1.5–4.5 μm in diam., subhymenial hyphae hyaline or rarely brownish, thin- to slightly thick-walled, predominantly interwoven, 1.5–3 μm in diam., basidia-bearing hyphae poorly differentiated, with a distinct wall, 2–4 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, as a rule small, angular; amorphous brownish or rusty-brown, CB (+) concretions present, especially abundant in senescent and dark-colored specimens. Needle-like crystals appearing in CB-mounted microscopic slides after 2–3 hours. Cystidia abundant to rare, hyaline, thin-walled, distinctly tapering, strongly swollen at the base, more rarely clavate, sometimes irregularly constricted, 13–44 × 5–9 μm, occasionally with a refractive, CB + contents. Hyphidia hyaline, thin- to slightly thick-walled, with a hyphoid, sinuous stem, 12–32 × 2–5.5 μm, in older basidiomata with a refractive, CB + contents, bearing several richly branched, hyaline apical outgrowths, 0.8–1.2 μm in diam. at the very apex, covering basidia and often forming a continuous layer up to 10 μm thick; apical branches usually encrusted by small, densely arranged crystals and occasionally bearing brownish amorphous matter. Basidia four-celled, ellipsoid-ovoid to nearly obconical, sessile, (13.5 –) 14–20.5 (– 22) × (7.2 –) 8.8–11.3 (– 12.2) μm (n = 33 / 3), thin- to slightly thick-walled, normally embedded, sometimes with a short stalk, up to 5 × 4 μm, sterigmata up to 15 × 2–3 μm; basidia in senescent hymenium with a distinctly thickened, gelatinized wall (up to 2 μm thick) and brownish cytoplasm. Basidiospores thin-walled, broadly to narrowly cylindrical, usually distinctly curved, (9.0 –) 9.1–13.4 (– 13.8) × (3.9 –) 4.0–6.1 (– 6.2) μm (n = 90 / 3), L = 10.49–11.46, W = 4.62–5.50, Q = 2.09–2.41, in older hymenium often with a distinct wall and brownish cytoplasm, glued in large groups.</p><p>Remarks.</p><p>Proterochaete furfurosa is morphologically similar and phylogenetically close to P. africana described above. Their differences are mentioned under the latter species. It is probably widely distributed in East Africa. Our current records confirm its presence in Uganda and Zimbabwe. Faded basidiomata of P. furfurosa are superficially similar to Adustochaete scalena occurring in the same geographic area. However, basidia and basidiospores of A. scalena are distinctly larger than those of P. furfurosa . Moreover, it lacks brownish amorphous deposits which are as a rule abundant in P. furfurosa .</p></div>	https://treatment.plazi.org/id/B5A14CA17EA15683B28DC87D067001E8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
49EDCC6FEF715F06980427DA19D852FD.text	49EDCC6FEF715F06980427DA19D852FD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete latispora (S. H. He, T. Nie & Yue Li) Spirin 2026	<div><p>Proterochaete latispora (S. H. He, T. Nie &amp; Yue Li) Spirin comb. nov.</p><p>≡ Heterocorticium latisporum S. H. He, T. Nie &amp; Yue Li, Journal of Fungi 9 (3, 318): 10, 2023. Holotype. China. Sichuan: Qionglai, Tiantaishan Forest Park, fallen angiosperm branch, 23 Sep 2012, He 20120923-20 * (BJFC 014667) .</p><p>Note.</p><p>This species was introduced as a member of Heterocorticium by Li et al. (2023) and is so far known from two localities in China. Our data place it in Proterochaete (Figs 3, 4). Proterochaete latispora differs from all other species of the genus in having ellipsoid basidiospores.</p></div>	https://treatment.plazi.org/id/49EDCC6FEF715F06980427DA19D852FD	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
DB8FAE903965554F896A431B723F35A0.text	DB8FAE903965554F896A431B723F35A0.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete letendreana (Pat.) Spirin 2026	<div><p>Proterochaete letendreana (Pat.) Spirin comb. nov.</p><p>Figs 30, 32 D, 33 A, B</p><p>≡ Sebacina letendreana Pat., Revue Mycologique 7: 152, 1885. Holotype. France. Seine-Maritime: Rouen, Le Grand-Quevilly, Colpoma quercinum and adjacent bark, 1883, Letendre (FH 00784209, studied) .</p><p>Description.</p><p>Basidiomata annual, effused, up to 10 cm in the longest dimension, waxy to arid, soft, 0.05–0.5 mm thick. Hymenial surface smooth or irregularly warted, at first pure white to pale cream-colored, slowly turning to bluish-gray, then changing to light brownish-gray or chocolate-brown, in older basidiomata irregularly cracking and fading to grayish-white or nearly white. Margin at first pruinose to fibrillose, gradually thinning, white to grayish, then sharply delimited, sometimes slightly elevated, compact, cream-colored, up to 1 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or rarely brownish, thin- to slightly thick-walled, subparallel or interwoven, 2–5 μm in diam., subhymenial hyphae hyaline, thin-walled or with a distinct wall, ascending or interwoven, 1.5–4 μm in diam., basidia-bearing hyphae thin-walled or with a distinct wall, 2.5–5 (6) μm in diam., in some specimens poorly differentiated. Crystals usually abundant in all parts of basidiomata, often encrusting hyphae, in juvenile and vigorously growing basidiomata predominantly small, angular or sand-like, then variably shaped; amorphous brownish or rusty-brown, CB + concretions present, especially abundant in senescent and dark-colored specimens. Cystidia absent. Hyphidia hyaline or brownish, thin- to slightly thick-walled, with a cystidia-like, fusiform or hyphoid stem, 14–36 × 2–6 μm, bearing several richly branched, hyaline or brownish apical outgrowths, 1–2 μm in diam. at the very apex; apical branches usually encrusted by small, densely arranged crystals and brownish amorphous matter. Basidia four-celled, ellipsoid-ovoid to obconical, sessile, (14 –) 14.5–22.5 (– 25) × (9.2 –) 9.4–15.8 (– 17.6) μm (n = 132 / 13), thin-walled (in senescent hymenium slightly thick-walled and agglutinated), normally embedded, sometimes with a short stalk, up to 5 × 4 μm, sterigmata up to 30 × 3.5–4 μm. Basidiospores thin-walled, broadly to narrowly cylindrical, slightly to distinctly curved, (9.3 –) 10.1–21.8 (– 24.7) × (4.6 –) 4.7–7.2 (– 7.6) μm (n = 600 / 21), L = 12.10–16.23, W = 5.19–6.63, Q = 2.10–2.78.</p><p>Remarks.</p><p>Proterochaete letendreana is widely distributed in Europe, from the Mediterranean to the southern part of Finland. It occurs predominantly on still hanging or just fallen, often corticated branches of many angiosperm tree species, as well as on dead shrub and grass stems and lianas, and produces basidiomata throughout the year. Proterochaete letendreana is exceptionally variable in both macroscopic and microscopic terms, and it is not surprising that its identity remained obscure prior to the present study.</p><p>This species was described as Sebacina letendreana by Patouillard (1885) from the north-western part of France. The type specimen, although small, is in a very good condition, fertile, and represents P. letendreana in its typical mature state, i. e. showing a brown hymenium and paler margin. Bourdot and Galzin (1927) interpreted it as a form of their broadly defined Sebacina calcea . Since then, S. letendreana had been treated merely as a synonym of Exidiopsis calcea sensu auct. (Pilát 1957; Wells 1961; Donk 1966; Wells and Raitviir 1977). The first sequence of P. letendreana was published by Weiß and Oberwinkler (2001) and named Exidiopsis sp. (GenBank AF 291282). A few other sequences of this species were submitted to GenBank afterwards, some of them mislabelled as Exidiopsis effusa (e. g., MZ 159758).</p><p>Morphologically, P. letendreana is similar to three other species occurring in Europe on angiosperm hosts, i. e. Adustochaete hiemalis, Leiostroma farinellum, and L. incanum . The latter three species possess softer basidiomata than P. letendreana, consisting of rather loosely arranged, spaced hyphae, and none of them has brownish, amorphous, cyanophilous deposits among their tissues. These deposits can be very rare, however, especially in pale-colored juvenile or faded senescent basidiomata of P. letendreana . In these cases, P. letendreana can be separated from A. hiemalis due to its smaller basidia and the lack of cystidia, as well as partly glued hyphae. In turn, the two Leiostroma species have much more extensive crystalline encrustation than P. letendreana, often making continuous, solid shields on their hyphae. Moreover, some basidia and subhymenial hyphae of Leiostroma spp. occasionally bear grayish-brownish contents. These structures are hyaline in P. letendreana . Hyphidia of L. farinellum and L. incanum often form groups of 3–7, while they are usually single and quite irregularly arranged in P. letendreana .</p></div>	https://treatment.plazi.org/id/DB8FAE903965554F896A431B723F35A0	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
A1E6D424386053BB859ED1B6B71E28C5.text	A1E6D424386053BB859ED1B6B71E28C5.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete macrogyna (K. Wells & Raitviir) Spirin & A. Savchenko 2026	<div><p>Proterochaete macrogyna (K. Wells &amp; Raitviir) Spirin &amp; A. Savchenko comb. nov.</p><p>Fig. 32 E</p><p>≡ Exidiopsis griseobrunnea ssp. macrogyna K. Wells &amp; Raitviir, Mycologia 69: 1002, 1977. Holotype. Russia. Yakutia: Eveno-Bytantaysky Nat. Dist., Batagai-Alyta, Alnus fruticosa (decayed branch), 12 Aug 1972, Parmasto (TAAM 56485 *, studied) .</p><p>Description.</p><p>Basidiomata annual, effused, orbicular, gregarious, up to 1 cm in diam., soft, up to 0.2 mm thick. Hymenial surface smooth or indistinctly tuberculate, ochraceous-brownish to brown, in older parts partly gelatinized and fading to light grayish-brown, at first continuous, then deeply cracking. Margin at first white, adnate, pubescent, up to 0.3 mm wide, then concolourous with hymenial surface, sharply delimited, sometimes partly detaching.</p><p>Hyphal structure monomitic, hyphae clamped, occasionally CB (+); subicular hyphae hyaline, slightly to distinctly thick-walled (walls gelatinized), mostly subparallel, frequently anastomosing, sometimes densely encrusted by angular crystals, variably inflated, 2–7 μm in diam., subhymenial hyphae hyaline or yellowish, thin- to slightly thick-walled, interwoven or ascending, rather loosely arranged, in older hymenium partly agglutinated, 1.5–4.5 μm in diam., often twisted, occasionally irregularly inflated up to 6–7 μm in diam., basidia-bearing hyphae not differentiated. Crystals abundant or rare, distributed in all parts of basidiomata, encrusting hyphae, small, angular. Cystidia rare, thin- to slightly thick-walled, tapering-clavate, often sinuous and sometimes producing sparsely branched side outgrowths, 22–31 × 3.5–8 μm. Hyphidia hyaline, with a distinct wall or slightly thick-walled, with a hyphoid, often sinuous stem, 22–31 × 2–3 μm, bearing several richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex; apical branches rarely encrusted by small, sparsely arranged crystals, usually forming a continuous layer up to 25 μm thick. Basidia four-celled, ellipsoid-ovoid, sessile, (17 –) 17.5–25 (– 27) × (11.4 –) 11.9–15.2 (– 15.4) μm (n = 41 / 3), usually thin-walled (obtaining a distinct wall and partly agglutinated in senescent hymenium), mostly embedded, occasionally with a reduced stalk-like base, up to 5 × 4 μm, sterigmata up to 22 × 2.5–3 μm. Basidiospores thin-walled, cylindrical or cylindrical-subfusiform to nearly allantoid, more rarely broadly cylindrical, slightly or clearly curved, (12.9 –) 13.0–21.8 (– 23.3) × (5.3 –) 5.4–7.1 (– 7.3) μm (n = 92 / 3), L = 16.99–18.25, W = 6.14–6.42, Q = 2.66–2.98.</p><p>Remarks.</p><p>This taxon was described as a subspecies of Exidiopsis griseobrunnea (Wells and Raitviir 1977). Our data show that these taxa are not conspecific or even closely related, although they are macroscopically quite similar and occur on the same host tree ( Alnus fruticosa) in North Asia. Exidiopsis griseobrunnea ssp. macrogyna is a sister species of the North American E. paniculata, and they both belong to Proterochaete, while E. griseobrunnea s. str. is a member of Ulocolla (Figs 1, 2). Two paratypes of E. griseobrunnea ssp. macrogyna (TAAM 45888, TAAM 56815) are not conspecific with the holotype, and therefore they are excluded from the description above.</p><p>Proterochaete macrogyna is a distinctive species due to its small, orbicular, brown basidiomata with partly elevated and detaching margins. Microscopically, large basidia and basidiospores, as well as the presence of crystals easily separate it from Ulocolla griseobrunnea inhabiting the same host. The species is so far known from a few localities with a strongly continental climate in Yakutia, Siberia.</p></div>	https://treatment.plazi.org/id/A1E6D424386053BB859ED1B6B71E28C5	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
ED3EBB2C8FA95FE0B1C228C15AC42128.text	ED3EBB2C8FA95FE0B1C228C15AC42128.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete mucedinea (Pat.) Spirin & Viner 2026	<div><p>Proterochaete mucedinea (Pat.) Spirin &amp; Viner comb. nov.</p><p>Fig. 32 F</p><p>≡ Sebacina mucedinea Pat., Bulletin de l’Herbier Boissier 3: 60, 1895. Holotype. Ecuador. Pichincha: Quito, Pululahua, twigs on the ground, Feb 1892 Lagerheim (FH 00784210, studied) .</p><p>= Exidiopsis mucedinea (Pat.) K. Wells, Lloydia 20: 46, 1957.</p><p>Description.</p><p>Basidiomata annual, effused, at first small, patch-like, then fusing together and up to 8 cm in the longest dimension, arid, compact, up to 0.1 mm thick. Hymenial surface smooth, cream-colored to grayish, with occasional brownish spots, continuous or finely cracking. Margin at first whitish, pruinose, up to 0.3 mm wide, then concolourous with hymenial surface, rather clearly delimited.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or brownish, variably thick-walled, subparallel, tightly arranged, 1.5–3 μm in diam., subhymenial hyphae hyaline, thin- to slightly thick-walled, interwoven, rather densely arranged and partly agglutinated, 2–3 μm in diam., basidia-bearing hyphae often well-differentiated, hyaline, slightly thick-walled, 3–5 μm in diam. Crystals abundant in all parts of basidiomata, encrusting hyphae, small, angular. Cystidia rare, thin- to slightly thick-walled, tapering or almost clavate, 18–33 × 4–8 μm. Hyphidia hyaline or brownish, thin- to slightly thick-walled, with hyphoid stem, 18–38 × 2.5–4.5 μm, bearing several richly branched apical outgrowths, 1–2 μm in diam. at the very apex; apical branches encrusted by small, densely arranged crystals or covered by amorphous, brownish or rusty-brown, CB (+) substance. Basidia four-celled, narrowly ovoid to almost obconical, sessile, (16.5 –) 17–20.5 (– 22) × (8.2 –) 9.3–13.2 (– 13.4) μm (n = 33 / 2), thin-walled or with a distinct wall, embedded or exposed, occasionally with a reduced stalk-like base, up to 7 × 5 μm, sterigmata up to 30 × 3–4 μm. Basidiospores thin-walled, broadly cylindrical, mostly clearly curved, (10.1 –) 10.2–16.2 (– 16.8) × (5.2 –) 5.8–7.2 (– 8.2) μm (n = 62 / 2), L = 13.06–13.24, W = 6.48–6.55, Q = 2.00–2.05.</p><p>Remarks.</p><p>Patouillard and Lagerheim (1895) described this species from Ecuador as Sebacina mucedinea and mentioned S. letendreana from Europe as its look-alike. Here we reinstate S. mucedinea as a species of Proterochaete . The holotype of S. mucedinea is scanty and substerile (only two turgid spores were found) but with a well-developed hymenium. Morphologically, it is nearly identical to two recent specimens from Argentina used for DNA study. Macroscopically, P. mucedinea is very similar to another neotropical species, P. stipidosa (see description below). These species can be separated from each other primarily by the size of their basidia and basidiospores (clearly smaller in P. stipidosa than in P. mucedinea).</p></div>	https://treatment.plazi.org/id/ED3EBB2C8FA95FE0B1C228C15AC42128	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
F740719BBD585ECC867AC9EA27CC6276.text	F740719BBD585ECC867AC9EA27CC6276.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete paniculata (K. Wells & Bandoni) Spirin & Viner 2026	<div><p>Proterochaete paniculata (K. Wells &amp; Bandoni) Spirin &amp; Viner comb. nov.</p><p>Fig. 32 G</p><p>≡ Exidiopsis paniculata K. Wells &amp; Bandoni, Mycologia 79: 283, 1987. Holotype. Canada. British Columbia: Vancouver, University of British Columbia Campus, Robinia pseudoacacia (fallen decorticated branch), 6 Jan 1983, Bandoni 6931 (BPI 871729 – isotype, studied) .</p><p>Description.</p><p>Basidiomata annual, effused, often gregarious, up to 2 cm in the longest dimension, waxy, up to 0.15 mm thick. Hymenial surface smooth or indistinctly tuberculate, light ochraceous to brownish, in older parts partly gelatinized and fading to grayish-white, at first continuous, then deeply cracking. Margin at first white, pruinose or pubescent, up to 1 mm wide, then concolourous with hymenial surface, sharply delimited.</p><p>Hyphal structure monomitic, hyphae clamped, occasionally CB (+); subicular hyphae hyaline, slightly to distinctly thick-walled (walls gelatinized), subparallel, often in tightly arranged bundles (up to 50 μm in diam.), frequently anastomosing, 2–5 μm in diam., subhymenial hyphae hyaline, thin- to slightly thick-walled, interwoven or ascending, rather loosely arranged, in older hymenium partly agglutinated, 2–6 (7) μm in diam., basidia-bearing hyphae usually well-differentiated, hyaline, thin-walled, 3–5 μm in diam., showing a zigzag-like branching pattern. Crystals abundant or rare, distributed in all parts of basidiomata, encrusting hyphae, small, angular. Needle-like crystals appearing in CB-mounted microscopic slides after 2–3 hours. Cystidia absent. Hyphidia hyaline, thin-walled or with a distinct wall, with a hyphoid or subfusiform, often sinuous stem, 19.5–52 × 4–8.5 μm, bearing several richly branched apical outgrowths, 1–2 μm in diam. at the very apex; apical branches encrusted by small, sparsely arranged crystals or bearing small brownish resinous droplets, occasionally forming a continuous layer up to 10 μm thick. Basidia four-celled, predominantly ellipsoid-ovoid, more rarely nearly obconical, sessile, (14 –) 14.5–22 (– 24) × (10.7 –) 11.1–15.7 (– 15.8) μm (n = 53 / 5), usually thin-walled (obtaining a distinct wall and partly agglutinated in senescent hymenium), mostly embedded, occasionally with a reduced stalk-like base, up to 5 × 3 μm, sterigmata up to 35 × 3–4 μm. Basidiospores thin-walled, cylindrical or cylindrical-subfusiform to nearly allantoid, mostly clearly curved, (11.0 –) 12.0–21.0 (– 23.2) × (4.3 –) 4.6–7.1 (– 7.2) μm (n = 110 / 4), L = 14.58–17.39, W = 5.14–5.82, Q = 2.54–3.39.</p><p>Remarks.</p><p>Exidiopsis paniculata was described from British Columbia, Canada, and previously known only from the type locality (Wells 1987). We succeeded in sequencing the paratype of E. paniculata from the locus classicus and could connect it to our recent specimens from Washington, USA. The improved species description above is based on type studies and morphological evidence from the US collections. Our data show that E. paniculata belongs to Proterochaete and that it is the closest relative of the North Asian P. macrogyna described above (Figs 1, 2). According to our observations, the spore variation range in P. paniculata is wider than mentioned in the protologue.</p><p>Proterochaete paniculata produces small, dark-colored, resupinate basidiomata on corticated, attached or freshly fallen branches of angiosperms. It is probably widely distributed along the North American Pacific coast and just overlooked due to its small size and dark coloration. Morphologically, it is highly similar to the European P. letendreana . The latter species, however, does not show any signs of gelatinization of the hymenium, while the hymenium layer is at least partly gelatinized and hygroscopic in older basidiomata of P. paniculata . The sister species of P. paniculata, P. macrogyna, has orbicular basidiomata with a partly detached margin (vs. corticioid basidiomata with adnate margin in P. paniculata). Moreover, it has wider hyphae, as well as wider and more clearly curved basidiospores than P. paniculata . Proterochaete paniculata is an acystidiate species. Proterochaete macrogyna has hymenial cystidia although they are usually quite rare. Differences between P. paniculata and P. abstrusa are discussed under the latter species.</p></div>	https://treatment.plazi.org/id/F740719BBD585ECC867AC9EA27CC6276	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
63614E48E05B5320A99CF50A8D580ADB.text	63614E48E05B5320A99CF50A8D580ADB.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete Spirin & Malysheva	<div><p>Proterochaete Spirin &amp; Malysheva, Botany 97: 447, 2019</p><p>= Heterocorticium S. H. He, T. Nie &amp; Yue Li, Journal of Fungi 9 (3, 318): 7, 2023. Generic type. Heterocorticium bambusicola S. H. He, T. Nie &amp; Yue Li, Journal of Fungi 9 (3, 318): 7, 2023.</p><p>Description.</p><p>Basidiomata annual, effused, waxy and semitranslucent to arid and opaque, nearly white to gray or brownish to brown. Hymenial surface smooth or (in one species) spinulose. Hyphal structure monomitic; hyphae clamped, hyaline or rarely brownish, often densely arranged and at least partly agglutinated, basidia-bearing hyphae variably differentiated. Crystals occasional to abundant, usually angular. Cystidia present or absent. Hyphidia present, with a well-differentiated stem and richly branched, densely encrusted apical outgrowths, in some species bearing amorphous brown cyanophilous substance. Basidia four-celled, ellipsoid-ovoid to obconical, sessile, thin- or slightly thick-walled, exposed or embedded, occasionally with a reduced stalk-like base. Basidiospores thin-walled, cylindrical to nearly allantoid, curved, more rarely ellipsoid. On dead wood of angiosperms.</p><p>Generic type.</p><p>Sebacina adusta Burt.</p><p>The genus Proterochaete was introduced as monotypic, with Sebacina adusta as the sole species and generic type (Alvarenga et al. 2019). It was justified via phylogenetic evidence which showed that the species is quite isolated from the rest of the Auriculariaceae genera sampled at the time. Morphologically, Proterochaete was separated from the rest of the Exidiopsis - like taxa because of a highly peculiar combination of macroscopic traits in the type species, i. e. spinulose hymenophore and partly detaching, fimbriate and occasionally rhizomorphic basidiome margin. However, our current data impel us to expand the genus with ten more species, none of which has the aforementioned macroscopic features.</p><p>In the current scope, Proterochaete can be separated from the other Exidiopsis / Heterochaete - like genera of the Auriculariacae ( Adustochaete, Eichleriella, Exidiopsis s. str., Heteroradulum, Leiostroma, and Ulocolla pr. p.) due to the following characters. First, all but two Proterochaete spp. possess abundant, small, as a rule angular crystals on their hyphae and hymenial cells. This feature rules out Eichleriella, Exidiopsis, Tegmenticium, and Ulocolla spp. Basidia of many Proterochaete spp. vary from ellipsoid-ovoid to obconical; in the latter case, they are reminiscent of the basidial cells in Heteroradulum . They are, however, devoid of the well-developed basal stalk characteristic of Heteroradulum spp. Moreover, most Heteroradulum spp. are dimitic while all species of Proterochaete are strictly monomitic. Differences between Proterochaete and Adustochaete are discussed under the latter genus.</p><p>As for Leiostroma, it differs from the outwardly similar Proterochaete spp. ( P. africana, P. furfurosa, P. letendreana, and P. mucedinea) in having softer basidiomata consisting of rather loosely arranged, not glued hyphae which often bear solid crystalline incrustation. In addition, hyphae and hyphidia of the listed Proterochaete spp. bear brownish amorphous granules well visible in CB (Fig. 30); these deposits are especially common in mature and senescent basidiomata where they fuse together and form large, amorphous, distinctly cyanophilous concretions. Moreover, most Proterochaete spp. have true cystidia and basidia-bearing hyphae of some species are poorly differentiated from the surrounding subhymenial hyphae. In contrast, all Leiostroma spp. described above are acystidiate and their basidia-bearing hyphae are wider than the subhymenial ones and thus easily detectable. See further remarks under P. letendreana .</p><p>Proterochaete abstrusa and P. adusta are the only species in the genus with a somewhat deviating morphology. They are totally devoid of a coarse crystalline encrustation, and their mature basidiomata are at least partly gelatinized, not waxy-arid as in other Proterochaete species. They are, however, otherwise very similar to other representatives of the genus, especially to P. macrogyna and P. paniculata . The superficially similar Eichleriella spp. can be separated from the mentioned Proterochaete species due to a distinctive subicular layer consisting of variably thick-walled, predominantly subparallel, spaced (not glued) and often brownish hyphae.</p></div>	https://treatment.plazi.org/id/63614E48E05B5320A99CF50A8D580ADB	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
3C01854D21E6541586E3DCCFAEF68BC3.text	3C01854D21E6541586E3DCCFAEF68BC3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Proterochaete stipidosa Viner & Spirin 2026	<div><p>Proterochaete stipidosa Viner &amp; Spirin sp. nov.</p><p>Fig. 32 H</p><p>Holotype.</p><p>Argentina • Misiones: Iguazu, Reserva Selva Iryapú, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-54.55692&amp;materialsCitation.latitude=-25.61405" title="Search Plazi for locations around (long -54.55692/lat -25.61405)">near IMiBio (Instituto Misionero de Biodiversidad)</a>, secondary forest, - 25.61405, - 54.55692, angiosperm branch, 7 May 2024, Viner 2024 / 266 * (H, isotype – SLP) .</p><p>Etymology.</p><p>Stipidosus (Lat., adj.) – woody, ligneous.</p><p>Description.</p><p>Basidiomata annual, effused, up to 3 cm in the longest dimension, arid, compact, up to 0.05 mm thick. Hymenial surface smooth, cream-colored to grayish, continuous or finely cracking. Margin pruinose, up to 0.3 mm wide, concolourous with hymenial surface.</p><p>Hyphal structure monomitic, hyphae clamped, CB (+); subicular hyphae hyaline, with a distinct wall, subparallel, tightly arranged, 1.5–3 μm in diam., subhymenial hyphae hyaline, with a distinct wall, interwoven or ascending, densely arranged and partly agglutinated, 1.5–4 μm in diam., basidia-bearing hyphae well-differentiated, hyaline, with a distinct wall, 3–5 μm in diam. Brownish deposits abundant in all parts of basidiomata, encrusting hyphae and hymenial cells, small, angular, CB +. Cystidia (gloeocystidia) abundant, hyaline or brownish, thin- to slightly thick-walled, tapering or clavate, 20–34 × 5–9.5 μm, rarely bi- or trifurcate, contents homogeneous, CB (+). Hyphidia hyaline or brownish, thin- to slightly thick-walled, with a hyphoid stem, 17–43 × 2–6 μm, bearing several richly branched apical outgrowths, 1–1.5 μm in diam. at the very apex, some hyphidia with CB + contents. Basidia four-celled, ellipsoid-ovoid, more rarely nearly obconical, sessile, (12 –) 13–15 (– 15.5) × (7.3 –) 7.8–9.2 (– 10.2) μm (n = 23 / 1), with a distinct wall or slightly thick-walled, embedded or exposed, occasionally with a reduced stalk-like base, up to 3 × 3 μm, sterigmata up to 25 × 2–3 μm. Basidiospores thin-walled, broadly cylindrical to cylindrical, slightly or moderately curved, (8.1 –) 8.6–11.3 (– 11.8) × (4.3 –) 4.4–5.3 (– 5.4) μm (n = 21 / 1), L = 13.06, W = 4.99, Q = 2.00.</p><p>Remarks.</p><p>Proterochaete stipidosa is described here as a close relative of P. mucedinea . Both species occur in the neotropics and can be distinguished based on the size of basidia and basidiospores (see remarks on P. mucedinea). Proterochaete stipidosa is so far known from the type locality in Argentina. However, its distribution area could be much wider – it seems that older descriptions of Exidiopsis mucedinea (Wells 1961; Lowy 1971) at least partly cover this species. We studied two specimens from Mexico which could be conspecific with P. stipidosa (Suppl. material 1). They are, however, more warmly colored (pale buff to pale orange), thicker and deeply cracking, and possess slightly longer basidia and basidiospores than the type specimen of P. stipidosa . It is impossible to decide based on morphology if they represent P. stipidosa in a more developed condition or belong to yet another species. This problem should be properly addressed after obtaining sequenced material from Mexico.</p></div>	https://treatment.plazi.org/id/3C01854D21E6541586E3DCCFAEF68BC3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
1206350529225C39A1B92EE061C2368D.text	1206350529225C39A1B92EE061C2368D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Scrupulispora perparvula Spirin & Viner 2026	<div><p>Scrupulispora perparvula Spirin &amp; Viner sp. nov.</p><p>Fig. 34</p><p>Holotype.</p><p>France • Aveyron: Millau, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=3.112&amp;materialsCitation.latitude=44.09705" title="Search Plazi for locations around (long 3.112/lat 44.09705)">Dourbie</a>, 44.09705 3.112, Acer campestre (fallen, partly corticated branch), 15 Nov 2022, Spirin 16358 * (H, isotype – PC) .</p><p>Etymology.</p><p>Perparvulus (Lat., adj.) – extremely tiny.</p><p>Description.</p><p>Basidiomata annual, effused, smooth, seen as a grayish bloom when rehydrated, inconspicuous when dry, up to 1 cm in widest dimension, 0.02–0.03 mm thick. Margin not differentiated.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, with a distinct wall or slightly thick-walled, interwoven or subparallel, frequently anastomosing, often agglutinated, 1–4 μm in diam., subhymenial hyphae hyaline, thin-walled or with a distinct wall, interwoven, agglutinated, 1–3.5 μm in diam., basidia-bearing hyphae not differentiated. Cystidia abundant, hyaline, thin-walled, clavate or distinctly tapering, occasionally pleural, embedded or slightly projecting, 11–23 × 5–11 μm, with homogeneous, CB (+) contents. Acanthophyses infrequent, hyaline, thin-walled, 11–14 × 2.5–8.5 μm, bearing up to five pointed, variably arranged protuberances, up to 6 × 1–2 μm. Hyphidia abundant, variably branched, 0.8–2 μm in diam., scattered among basidia. Basidia four-celled, broadly ellipsoid to subglobose, sessile, occasionally with a distinctly narrowed, stipe-like base, (10.8 –) 11.2–19.2 (– 21.6) × (9.0 –) 9.2–12.8 (– 13.2) μm (n = 40 / 2), thin-walled, often covered by shields of hyphidia and remnants of collapsed basidia, sterigmata up to 8 × 2–3.5 μm. Basidiospores with a distinct wall (up to 0.3 μm), smooth or more often minutely warted, broadly ellipsoid, rarely subglobose or nearly lacrymoid, (7.1 –) 7.2–11.1 (– 11.2) × (5.2 –) 5.8–9.2 (– 10.2) μm (n = 60 / 2), L = 8.14–9.18, W = 6.73–7.44, Q = 1.21–1.24, apiculus thick and blunt, up to 1.5 × 2 μm, occasionally somewhat eccentric.</p><p>Remarks.</p><p>Diagnostic features of S. perparvula differentiating it from the similar representatives of the Auriculariaceae are discussed above. We introduce this species based on two collections from Austria and France. An unnamed environmental ITS sequence JN 858124 (GenBank) belongs to S. perparvula . It was obtained from cork samples of Quercus suber in Portugal (Barreto et al. 2012). This suggests that S. perparvula may be widely distributed in the southern part of Europe.</p></div>	https://treatment.plazi.org/id/1206350529225C39A1B92EE061C2368D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
FC0E283DE01C52628A05BF42BF1B87EC.text	FC0E283DE01C52628A05BF42BF1B87EC.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Scrupulispora Spirin & Viner 2026	<div><p>Scrupulispora Spirin &amp; Viner gen. nov.</p><p>Etymology.</p><p>From ‘scrupulus’ (Lat., noun), a grain of sand, and ‘spora’; in reference to the occasionally encrusted basidiospore wall.</p><p>Description.</p><p>Basidiomata annual, effused, smooth, hardly visible, margin not differentiated. Hyphal structure monomitic, hyphae clamped, hyaline; basidia-bearing hyphae not differentiated. Cystidia abundant, hyaline, thin-walled, clavate or distinctly tapering. Acanthophyses occasionally present, thin-walled, bearing up to five pointed, variably arranged protuberances. Hyphidia abundant, variably branched, scattered among basidia. Basidia four-celled, broadly ellipsoid to subglobose, sessile, thin-walled, often covered by shields of hyphidia and remnants of collapsed basidia. Basidiospores with a distinct wall, smooth or minutely warted, broadly ellipsoid, more rarely subglobose or nearly lacrymoid, repetitive, occasionally germinating with 2–3 tubes, apiculus thick and blunt. On dead wood of angiosperms.</p><p>Generic type.</p><p>Scrupulispora perparvula .</p><p>This genus is introduced here as monotypic, with S. perparvula as the single species. It belongs to Auriculariaceae and is probably related to Oliveonia (Fig. 2). The two genera share some important morphological traits, such as ephemeral, inconspicuous basidiomata, tapering hymenial cystidia, and small basidia with rather long sterigmata. The presence of acanthophyses in Scrupulispora makes it similar to Heteroacanthella . However, all known Heteroacanthella species are devoid of cystidia and their basidia are one-celled, bearing one or two sterigmata (Oberwinkler et al. 1990; Roberts 1999). Moreover, the basidiospores of Oliveonia and Heteroacanthella spp. are smooth; in S. perparvula, their wall usually bears small, sand-like, cyanophilous, irregularly distributed deposits. We were able to observe this encrustation in both turgid and half-collapsed, empty spores. Therefore, we suppose that the presence of these deposits is more or less permanent, and it may serve as a diagnostic trait of S. perparvula . Among the Auriculariales, only a few Basidiodendron spp. also have ornamented basidiospores. They, however, do not belong to the Auriculariaceae (Spirin et al. 2021, 2025).</p></div>	https://treatment.plazi.org/id/FC0E283DE01C52628A05BF42BF1B87EC	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
729CE83417075AFD95AC1198388BDEDD.text	729CE83417075AFD95AC1198388BDEDD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Sebacina candida L. S. Olive 1898	<div><p>Sebacina candida L. S. Olive, Bulletin of the Torrey Botanical Club 85: 21, 1958</p><p>Holotype.</p><p>Tahiti • Faa Tautia Valley, corticated dead limbs, 9 Aug 1956, Olive T 442 (NY 00738349, studied) .</p><p>After studying the type specimen of S. candida, we concluded that it is most likely a member of Proterochaete and it probably belongs in the vicinity of P. latispora, another representative of the genus with distinctly ellipsoid basidiospores. However, the basidiospores of S. candida are clearly smaller than in P. latispora, 6.8–9.3 × 5.1–6.0 μm (n = 8). The identity of S. candida should be re-established based on sequenced material from Polynesia. Wells (1961) combined S. candida in Exidiopsis and reintroduced it based on a wider set of specimens from the neotropics. However, the conspecificity of this material with S. candida s. typi is questionable. Furthermore, Wells (ibid.) mentioned Tremella sordida Speg. originally described from Tierra del Fuego as an older name for S. candida which eventually could not have been combined in Exidiopsis, due to the existence of Exidiopsis sordida (S. L. Olive) K. Wells (= Sebacina sordida S. L. Olive). The latter species was compared by Wells with the European E. grisea (= Ulocolla grisea in the present study). No modern, sequenced material is known to us for either T. sordida or S. sordida .</p></div>	https://treatment.plazi.org/id/729CE83417075AFD95AC1198388BDEDD	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
3122F253EE735EAEA3596AC1944A543D.text	3122F253EE735EAEA3596AC1944A543D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Sebacina glauca Pat.	<div><p>Sebacina glauca Pat., Bulletin de la Société Mycologique de France 9: 140, 1893</p><p>Holotype.</p><p>Ecuador • Pichincha, dead branches, Mar 1892, Lagerheim (FH 00060387, studied) .</p><p>Sebacina glauca was described from Ecuador (Patouillard and Lagerheim 1893) and it remains known from the type material only. The type specimen is in good condition and fertile. Morphological traits point to Proterochaete (especially to P. macrogyna and P. paniculata) as the most appropriate genus for S. glauca . However, we refrain from making a formal recombination of it in Proterochaete before obtaining more material and DNA sequences. Wells (1961) placed S. glauca in the synonyms of the widely defined Exidiopsis grisea (= Ulocolla grisea in the present study). However, this synonymy should be abandoned.</p></div>	https://treatment.plazi.org/id/3122F253EE735EAEA3596AC1944A543D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
14BFD2AB3D60505FA160FE7654887098.text	14BFD2AB3D60505FA160FE7654887098.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Sebacina livescens Bres. 1898	<div><p>Sebacina livescens Bres., Fungi Tridentini 2 (11–13): 64, 1898</p><p>Type materials.</p><p>Lectotype (selected by Spirin et al. 2025: 370). Italy • Trentino-Alto Adige: Trento, Andalo, Abies alba (rotten log), Aug 1896, Bresadola (S F 29132, studied) .</p><p>The species was combined in Exidiopsis by Bourdot and Maire (1920). It was recently shown to be a member of Protohydnum (Auriculariales) (Spirin et al. 2025) .</p></div>	https://treatment.plazi.org/id/14BFD2AB3D60505FA160FE7654887098	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
D7F769DEEA4D56398B81555378C1B2FE.text	D7F769DEEA4D56398B81555378C1B2FE.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Sebacina opalea Bourdot & Galzin 1898	<div><p>Sebacina opalea Bourdot &amp; Galzin, Bulletin de la Société Mycologique de France 39: 262, 1924</p><p>Note.</p><p>Sebacina opalea was described from France (Bourdot and Galzin 1924, 1927) and later reintroduced as a member of Exidiopsis by Reid (1970) and Roberts (1993). The species has not been formally typified yet. However, our study of the authentic material, as well as newly collected specimens confirm that S. opalea should be removed from the Auriculariales . Its reintroduction and taxonomic replacement is the subject of a forthcoming publication.</p></div>	https://treatment.plazi.org/id/D7F769DEEA4D56398B81555378C1B2FE	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
ADDF6B5F6ED55997A195B562A3347183.text	ADDF6B5F6ED55997A195B562A3347183.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Sebacina umbrina D. P. Rogers	<div><p>Sebacina umbrina D. P. Rogers, University of Iowa Studies in Natural History 17: 38, 1935</p><p>Note.</p><p>This species was originally described from Iowa, USA (Rogers 1935) and later reported from Denmark (Christiansen 1959) and Germany (Oberwinkler 1963). Descriptions of S. umbrina by the latter authors certainly refer to dark-colored individuals of Proterochaete letendreana, which is widely distributed in temperate Europe. We had no opportunity to study the type material of S. umbrina and its identity therefore remains unclear. Wojewoda (1981) combined S. umbrina in Exidiopsis . However, its taxonomic position should be reassessed based on DNA data.</p></div>	https://treatment.plazi.org/id/ADDF6B5F6ED55997A195B562A3347183	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
E11E6F853B715E79883BF034A6738C55.text	E11E6F853B715E79883BF034A6738C55.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Tegmenticium peritrichum (Bourdot & Galzin) Spirin, Viner & Rivoire 2026	<div><p>Tegmenticium peritrichum (Bourdot &amp; Galzin) Spirin, Viner &amp; Rivoire comb. nov.</p><p>Figs 33 C, 35, 36 A</p><p>≡ Sebacina peritricha Bourdot &amp; Galzin, Bulletin de la Société Mycologique de France 25: 26, 1909. Lectotype (selected here, MBT 10031461). France. Aveyron: Millau, Massebiau, Pyrus sp., Nov 1907, Galzin 2278 (herb. Bourdot 5159) (PC, studied) .</p><p>= Exidiopsis peritricha (Bourdot &amp; Galzin) Sacc. &amp; Trotter, Sylloge Fungorum 21: 452, 1912.</p><p>= Exidiopsis gypsea K. Wells &amp; Raitv., Mycologia 69: 995, 1977. Holotype. Estonia. Ida-Virumaa: Illuka, Puhatu Nat. Res., Ulmus glabra (fallen twig), 4 Oct 1967, Parmasto (TAAM 016907 *, studied) .</p><p>Description.</p><p>Basidiomata annual, first waxy-gelatinous, adpressed-orbicular, up to 1 cm diam., then fusing together, crust-like, gelatinous, up to 20 cm in the longest dimension, 0.1–0.2 mm thick. Hymenial surface smooth or indistinctly warted, entirely covered by a grayish-white, easily removable pruina, often fading to almost white in herbarium, occasionally with scattered brownish flecks, in older basidiomata often cracking and showing a darker (amber-colored to reddish-brown) inner layer. Margin compact, sharply delimited, sometimes slightly elevated, in some specimens adnate, pubescent, nearly white or grayish, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, thin- to slightly thick-walled, interwoven or subparallel, 2–4 μm in diam., occasionally irregularly inflated (up to 5 μm in diam.), subhymenial hyphae hyaline or yellowish, thin-walled or with a distinct wall, ascending or interwoven, some twisted, agglutinated, 1.5–3.5 μm in diam., rarely irregularly inflated (up to 5 μm in diam.), basidia-bearing hyphae as a rule poorly differentiated, thin-walled, 2–3 μm in diam., often showing a zigzag-like branching pattern. Crystals as a rule absent; if present, then very rare, scattered, varying from small angular to large rhomboid, up to 15 μm in the longest dimension. Cystidia hyaline, thin-walled, abundant or infrequent, usually clearly tapering, some sinuous, rarely bifurcate, 16–70 × 3.5–13 μm, in senescent hymenium occasionally with yellowish-brownish contents. Hyphidia hyaline, more rarely with a yellowish-brownish, CB (+) contents, richly branched, with a thin-walled, subfusiform or hyphoid, often sinuous stem, up to 50 × 3–9 μm, apical branches not encrusted, 1–2 (2.5) μm in diam., often agglutinated, covering basidia and forming a continuous layer up to 30 μm thick. Probasidia clavate or tapering, 11–16 × 6–9 μm. Basidia (two-) four-celled, ellipsoid-ovoid to subglobose, sessile, (11.5 –) 12–18 (– 18.5) × (8.1 –) 8.3–12.6 (– 12.7) μm (n = 127 / 12), thin-walled, sometimes obliquely septate, partly agglutinated, embedded, occasionally with a short stalk-like base, up to 5 × 3 μm, sterigmata up to 45 × 2–2.5 μm. Basidiospores thin-walled, broadly to narrowly cylindrical, often distinctly curved, (8.3 –) 8.9–15.1 (– 16.1) × (3.6 –) 3.8–6.5 (– 7.2) μm (n = 457 / 15), L = 10.44–12.88, W = 4.31–5.74, Q = 2.08–2.76.</p><p>Remarks.</p><p>This species was introduced by Bourdot and Galzin (1909) as Sebacina peritricha . In their later work (Bourdot and Galzin 1927), they treated it as a subspecies of Sebacina uvida (Fr.) Bourdot &amp; Galzin sensu auct. (= Exidiopsis effusa in the current sense; see Larsson et al. (2025) for further comments on the identity of Thelephora uvida Fr.). Wells (1961) listed S. peritricha among the synonyms of his widely defined E. grisea . Subsequently, it was included in the synonymy of E. effusa (Wells and Raitviir 1977) . Fourteen specimens labelled as S. peritricha exist in herbarium of Bourdot (PC). Of them, eleven specimens are evidently conspecific, two (Maire 729 and 1202) are in poor condition, and one more (Galzin 6987) is a homobasidiomycete, most likely a species of Dendrothele s. lato. Four specimens were collected prior to the publication of S. peritricha and we select the best-preserved collection (Galzin 2278) as the lectotype of this species. Exidiopsis gypsea described from Estonia (Wells and Raitviir 1977) is conspecific with S. peritricha . ITS sequences obtained from the type specimen of E. gypsea are available in UNITE (UDB 07674230 and UDB 07674281).</p><p>Tegmenticium peritrichum is widely distributed in temperate – hemiboreal forests of Europe although seemingly rare everywhere. It inhabits dead, hanging or just fallen, often still corticated branches of many species of deciduous trees and shrubs.</p></div>	https://treatment.plazi.org/id/E11E6F853B715E79883BF034A6738C55	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
305E479CB8225585B0B94FAD2A6B73A5.text	305E479CB8225585B0B94FAD2A6B73A5.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Tegmenticium Spirin & Viner 2026	<div><p>Tegmenticium Spirin &amp; Viner gen. nov.</p><p>Etymology.</p><p>From ‘tegmen’ (short version of ‘tegimen’) (Lat., noun), meaning a cover or a clothing, and Corticium, in reference to the crust-like basidiomata.</p><p>Description.</p><p>Basidiomata annual, effused, waxy-gelatinous, opaque, grayish-white. Hymenial surface smooth, covered by a grayish-white, easily removable pruina. Hyphal structure monomitic; hyphae clamped, hyaline or yellowish, agglutinated, basidia-bearing hyphae poorly differentiated. Crystals normally absent. Cystidia present, thin-walled, hyaline, usually clearly tapering. Hyphidia present, with a well-differentiated stem and richly branched, non-encrusted apical outgrowths, forming a continuous layer. Basidia four-celled, ellipsoid-ovoid to subglobose, sessile, thin-walled, embedded, occasionally with a reduced stalk-like base. Basidiospores thin-walled, broadly to narrowly cylindrical, curved. On dead wood of angiosperms.</p><p>Generic type.</p><p>Sebacina peritricha Bourdot &amp; Galzin.</p><p>This genus is introduced here for a single species, Exidiopsis (Sebacina) peritricha, which is currently synonymized with E. effusa . Our data (Figs 1, 2) show that these species should be treated separately and that they are not closely related. Tegmenticium peritrichum is different from other European species formerly treated under Exidiopsis due to its well-developed cystidia, as well as its rather small basidia and basidiospores. Its mature basidiomata are clearly gelatinized and covered by a whitish-grayish, easily removable deposit. Thus, they can be mistaken for E. effusa . The latter species, however, lacks cystidia and has larger basidia and, in most specimens, longer basidiospores. Moreover, it possesses spine-like outgrowths on its hymenial surface, although they can be detected only in fresh or rehydrated specimens. Differences of T. peritrichum from the outwardly similar Exidia repleta and E. saturata are discussed above, under E. repleta . Proterochaete abstrusa occasionally bears cystidia which are similar to those of T. peritrichum . However, P. abstrusa can be easily recognized due to its slenderer basidiomata, larger basidiospores and basidia, as well as thicker sterigmata. See further notes under Ulocolla corticioides .</p></div>	https://treatment.plazi.org/id/305E479CB8225585B0B94FAD2A6B73A5	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
E42B97EC8F8E5B0A9E421FC79FBEDA68.text	E42B97EC8F8E5B0A9E421FC79FBEDA68.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla badioumbrina Bres.	<div><p>Ulocolla badioumbrina Bres., Annales Mycologici 1: 115, 1903</p><p>Syntypes.</p><p>Poland. [no exact locality indicated], Alnus glutinosa and Salix cinerea, Eichler (S F 20292, 20289, studied) .</p><p>Ulocolla badioumbrina was combined in Exidia by Killermann (1928). It was recently moved to the genus Globulisebacina (Sebacinales) (Friebes and Spirin 2025) .</p></div>	https://treatment.plazi.org/id/E42B97EC8F8E5B0A9E421FC79FBEDA68	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
A568E1E54F8E58539A14FB97E39BDC5A.text	A568E1E54F8E58539A14FB97E39BDC5A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla Bref.	<div><p>Ulocolla Bref., Untersuchungen aus dem Gesammtgebiete der Mykologie 7: 95, 1888</p><p>= Sclerotrema Spirin &amp; Malysheva, Fungal Biology 121: 712, 2017. Generic type. Exidiopsis griseobrunnea K. Wells &amp; Raitviir, Eesti NSV Teaduste Akadeemia Toimetised 15: 206, 1966.</p><p>Description.</p><p>Basidiomata annual, gelatinous, adpressed-orbicular or cerebriform, or resupinate, corticioid or stereoid, arid or only slightly gelatinized, grayish or brownish to dark brown. Abhymenial surface smooth; hymenial surface smooth or variably folded, spine-like projections absent in most species. Crystals occasionally present, angular, sometimes in large concretions. Hyphal structure monomitic; hyphae clamped, hyaline or yellowish, not encrusted, basidia-bearing hyphae variably differentiated. Cystidia absent in all but one stereoid species; hyphidia present, with thickened walls, forming a continuous layer, in mature basidiomata of most species often cemented by yellowish-brownish amorphous substance. Basidia four-celled, longitudinally, sometimes obliquely septate, ellipsoid-ovoid, sterigmata slender. Basidiospores hyaline, thin-walled, broadly cylindrical to allantoid, usually distinctly curved. On dead wood of angiosperms or conifers.</p><p>Generic type.</p><p>Exidia saccharina Fr. (selected by Clements and Shear 1931: 342).</p><p>The genus Ulocolla was described by Brefeld (1888) for two species, U. saccharina and U. foliacea . The first species was explicitly based on E. saccharina by Fries, while the second one was often considered as a recombination of Tremella foliacea Pers. (currently Phaeotremella foliacea (Pers.) Wedin et al., Tremellales). Brefeld’s description of U. foliacea clearly refers to U. saccharina with more distinctly lobate, foliaceous basidiomata and not to P. foliacea . However, his reference to Persoon’s T. foliacea in the beginning of the Ulocolla chapter of his book (Brefeld 1888: 95) makes it, formally, a new combination based on Persoon’s species. Clements and Shear (1931) selected E. saccharina as the generic type of Ulocolla .</p><p>As reintroduced here, Ulocolla encompasses seven species with rather divergent macroscopic traits. Three of them ( U. pinicola, U. saccharina, and U. subrepanda) were classified in Exidia, two ( U. grisea and U. griseobrunnea) in Exidiopsis, and one more ( U. corticioides) was considered merely a variety of the broadly defined Sebacina calcea (as var. corticioides). These species groups have never been discussed in connection to each other before or recognized as belonging to a joint monophyletic lineage. Our data firmly place them together (Figs 1, 2).</p><p>Despite their various macroscopic habits, Ulocolla spp. share several important anatomical traits which allow morphological recognition of this genus. First, basidiomata of most species show more or less pronounced brown pigmentation caused by yellowish or brownish cytoplasm of hyphae and hymenial cells and, in most cases, by the presence of amorphous yellowish-brownish exudates cementing apical branches of hyphidia and sometimes spreading among hymenial cells. Second, Ulocolla spp. have much more irregularly inflated hyphae than any other taxa treated in this study (except for Exidia repleta, E. saturata, and Exidiopsis s. str. spp.), which often show rather sharp transitions between normally looking, narrow and strongly widened, inflated hyphal segments. All Ulocolla spp. have ellipsoid-ovoid, often obliquely septate basidia sometimes having a tapering, stalk-like base and bearing slender sterigmata.</p><p>Four exidioid Ulocolla species ( U. orbiculata, U. pinicola, U. saccharina, and U. subrepanda) differ from the similar species of Exidia s. str. by the lack of granular encrustation on their hyphae and hyphidia. Moreover, they have hyphidia with variably thick-walled, brownish and often strongly inflated stems. No such structures have been observed in the brown-colored Exidia spp. ( E. candida and the E. recisa complex). In turn, hyphidia of the superficially similar Descidia repanda have narrow, hyphoid, rather evenly outlined stems.</p></div>	https://treatment.plazi.org/id/A568E1E54F8E58539A14FB97E39BDC5A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
641E65D55E515C6BA5606B53AFF4C93A.text	641E65D55E515C6BA5606B53AFF4C93A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla corticioides (Malencon) Spirin & Viner 2026	<div><p>Ulocolla corticioides (Malençon) Spirin &amp; Viner comb. nov.</p><p>Figs 33 D, 36 B</p><p>≡ Sebacina calcea var. corticioides Malençon, Bulletin Trimestriel de la Société Mycologique de France 70: 156, 1954. Lectotype (selected here, MBT 10034108). Morocco. Fez-Meknès: Ifrane, Michlifen, Quercus ilex (decorticated wood), 11 May 1953 Malençon 2419 (MPU 898044, studied) .</p><p>Description.</p><p>Basidiomata annual, initially patch-like, small, gregarious, waxy-arid, later fusing together and becoming harder (nearly leathery), crust-like, sometimes slightly gelatinized, opaque, 0.05–0.2 mm thick, up to 10 cm in the longest dimension. Hymenial surface smooth or indistinctly warted, first grayish-white or cream-colored, smooth, with scattered, brownish flecks, then indistinctly or clearly tuberculate, sometimes cracking, wood-colored to pale ochraceous, occasionally with distinct, reddish-brown dots or flecks, in senescent basidiocarps yellowish-brown. Margin first pruinose or pubescent, adnate, white, then compact, sharply delimited, in some specimens partly detaching, concolorous with hymenial surface, up to 0.5 mm wide.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, thin- to slightly thick-walled, interwoven or subparallel, anastomosing, occasionally in bundles, in older basidiocarps agglutinated, 2–4 μm in diam., occasionally distinctly inflated (up to 5–7 μm in diam.), subhymenial hyphae hyaline, grayish or yellowish, thin-walled or with a distinct wall, predominantly interwoven, tightly agglutinated, 1.5–3 μm in diam., occasionally irregularly inflated (up to 5 μm in diam.), basidia-bearing hyphae as a rule poorly differentiated, thin-walled or with a distinct wall, 2.5–4 μm in diam., sometimes showing a zigzag-like branching pattern. Crystals absent or accidental, angular, up to 10 μm in the longest dimension., rather abundant in senescent, substerile basidiocarps (and then in large groups up to 20 μm in diam.). Cystidia absent. Hyphidia hyaline, grayish or yellowish, richly branched, with a thin- or slightly thick-walled, subfusiform, nodulose or hyphoid, often sinuous stem, up to 70 × 2–11 μm, apical branches not encrusted, 0.8–1.5 μm in diam., often agglutinated, covering basidia and forming a continuous layer up to 30 μm thick. Probasidia clavate or tapering, 11–19 × 5.5–10 μm. Basidia four-celled, ellipsoid-ovoid to broadly ellipsoid, sessile, (11 –) 11.5–20.5 (– 21) × (8.3 –) 8.8–14.0 (– 15.3) μm (n = 116 / 7), thin-walled or with a distinct wall, occasionally with a tapering stalk-like base, up to 6 × 4 μm, embedded, sterigmata up to 35 × 2–4 μm. Basidiospores thin-walled, narrowly to broadly cylindrical, often distinctly curved, (8.9 –) 9.0–17.7 (– 18.3) × (3.9 –) 4.0–6.8 (– 6.9) μm (n = 215 / 7), L = 11.64–15.23, W = 4.31–5.93, Q = 2.39–3.02.</p><p>Remarks.</p><p>Ulocolla corticioides was originally described by Malençon (1954) from Morocco as a variety of the widely interpreted Sebacina calcea . We studied five authentic specimens of this taxon stored in MPU and selected one of them as a lectotype. One specimen (Uotila 40874) from the locus classicus was used for DNA study. The ITS sequence of this collection is identical to those of three our specimens of which one (Viner 2025 / 94 A) was included in the multigene phylogenies (Figs 1, 2). DNA data firmly place S. calcea var. corticioides close to Exidia saccharina, the generic type of Ulocolla . We therefore raise this variety to the species rank and combine it in Ulocolla .</p><p>Ulocolla corticioides is a southern species occurring mainly in the Mediterranean. Two historical collections from Öland, Sweden, are assigned to this species based on morphological study. We are not aware of other specimens of U. corticioides from temperate Europe. The species typically occurs on still standing and at least partly corticated, dead logs or dead, still attached branches of angiosperm trees ( Arbutus, Crataegus, Quercus). In the protologue, Malençon (1954) mentioned that some basidiomata of U. corticioides on fallen logs of Quercus in Morocco reached up to 1 m long. The ITS sequence of S. calcea AJ 427408 from Morocco (GenBank, obtained from CBS strain 463.62) belongs to U. corticioides .</p><p>Macroscopically, U. corticioides is most similar to Tegmenticium peritrichum described above. Senescent basidiomata of these species with brownish stains and flecks on the hymenial surface are especially similar. However, they are covered by a whitish pruina in T. peritrichum, which can be easily removed by the slightest touch, thus exposing a darker, gelatinous inner layer (Fig. 33 C). The basidiocarp structure of U. corticioides is different: a somewhat gelatinized layer, if present, is adjacent to the substrate and it shows not a striking difference but a gradual transition to non-gelatinous hymenial and epihymenial layers. Moreover, U. corticioides has on average longer basidiospores than T. peritrichum (although their dimensions partly overlap) and it lacks cystidia.</p><p>In the Mediterranean, U. corticioides may occur in the same habitats with Leiostroma incanum . The species show a certain morphological similarity to each other, especially in the younger stages. Ulocolla corticioides can be separated from L. incanum due to its tightly arranged, partly agglutinated, not encrusted hyphae and hyphidia, as well as poorly differentiated basidia-bearing hyphae.</p></div>	https://treatment.plazi.org/id/641E65D55E515C6BA5606B53AFF4C93A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
DD2F0ACFD4C159B9996C93C5E507B3D6.text	DD2F0ACFD4C159B9996C93C5E507B3D6.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla grisea (Bres.) Spirin 2026	<div><p>Ulocolla grisea (Bres.) Spirin comb. nov.</p><p>Figs 36 C, 37</p><p>≡ Sebacina grisea Bres., Annales Mycologici 6: 45, 1908.</p><p>= Thelephora grisea Pers., Mycologia Europaea 1: 149, 1822. Neotype (selected by Wells 1961: 343). France. [no locality indicated], Abies alba, 24 Apr 1900, Strasser (S F 350416, studied) .</p><p>= Exidiopsis grisea (Bres.) Bourdot &amp; Maire, Bulletin de la Société Mycologique de France 36: 71, 1920.</p><p>Description.</p><p>Basidiomata annual, effused, up to 10 cm in the longest dimension, rarely larger, gelatinous, semitranslucent, up to 0.5 mm thick. Hymenial surface grayish, smooth or indistinctly tuberculate in fresh condition, bluish-gray and shining in herbarium. Margin sharply delimited, adnate.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline or yellowish, thin- or slightly thick-walled, subparallel or interwoven, anastomosing, agglutinated, 1.5–4 μm in diam., subhymenial hyphae hyaline or yellowish, thin-walled, predominantly ascending, 1.5–4 μm in diam., occasionally inflated and then up to 5 μm in diam., basidia-bearing hyphae not differentiated. Crystals occasionally present, angular, scattered among hyphae, sometimes producing large concretions up to 25 μm in diam. Cystidia absent. Hyphidia thin-walled, with a thin-walled, hyaline, hyphoid or nodulose stem, 17–35 × 3–5 μm, and abundant, richly branched, hyaline apical outgrowths, 1–1.5 μm in diam. at the very apex, in older basidiomata partly embedded in gelatinous matrix and producing a continuous layer up to 30 μm thick. Probasidia usually tapering, more rarely narrowly clavate, 10–20 × 5–6 μm. Basidia four-celled, ellipsoid-ovoid to subglobose, occasionally with a distinctly narrowed, stalk-like base, (10 –) 10.5–15.5 (– 16) × (8.1 –) 8.3–12.2 (– 12.8) μm (n = 50 / 4), thin-walled, embedded, sterigmata up to 20 × 1.5–2 μm. Basidiospores thin-walled, broadly to narrowly cylindrical, distinctly curved, (9.0 –) 9.1–14.3 (– 15.1) × (3.9 –) 4.0–5.7 (– 5.8) μm (n = 180 / 6), L = 10.69–12.94, W = 4.60–5.06, Q = 2.23–2.62.</p><p>Remarks.</p><p>This species was first introduced by Persoon (1822) as Thelephora grisea . Although only macroscopic traits were mentioned in the protologue, there is a little doubt about the species Persoon dealt with – there are no other effused, semitranslucent, bluish-grayish, rather thick jelly fungi on coniferous wood in Europe. Unfortunately, Persoon’s T. grisea turned out to be a homonym of T. grisea Schwein.; the latter name was sanctioned by Fries (1828) and this made Persoon’s species name unavailable. It was resurrected by Bresadola (1908) who transferred T. grisea Pers. to Sebacina and thus made it available for future recombinations in other genera. Wells (1961) redescribed Exidiopsis grisea with a long list of synonyms which included, inter alia, E. effusa and Sebacina plumbescens . His view on the identity of E. grisea was contested by Donk (1966) and Reid (1970). Christiansen (1959), Oberwinkler (1963) and Wells and Raitviir (1977) reintroduced the species in the sense accepted here. No authentic material from Persoon is extant; Wells (1961) selected one of Bresadola’s specimens from Stockholm as a neotype of T. grisea .</p><p>Ulocolla grisea is closely related to U. orbiculata from Far East Asia. Their differences are listed under the latter species. Exidiopsis effusa is macroscopically somewhat similar to U. grisea . However, U. grisea is restricted to wood remnants of conifers (especially Abies and Pinus) while E. effusa occurs exclusively on angiosperm hosts. The hymenophore of E. effusa often bears sharp projections and covered by whitish, easily removable pruina. In contrast, basidiomata of U. grisea are completely smooth or indistinctly tuberculate and possess no deposits on hymenial surface. Moreover, E. effusa has wider hyphae than U. grisea, which are often quite irregularly inflated, and its basidia are larger and basidiospores are on average longer than in the latter species. Protohydnum livescens is another effused conifer-dwelling species with rather thick gelationous basidiomata occurring in Europe. It differs from U. grisea by the pronounced reddish or brownish tints of dried specimens, as well as in having pedunculate basidia and wider basidiospores (see description in Spirin et al. 2025).</p></div>	https://treatment.plazi.org/id/DD2F0ACFD4C159B9996C93C5E507B3D6	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
8699BED1430C53ED93914D76A9126576.text	8699BED1430C53ED93914D76A9126576.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla griseobrunnea (K. Wells & Raitviir) Spirin & Malysheva 2026	<div><p>Ulocolla griseobrunnea (K. Wells &amp; Raitviir) Spirin &amp; Malysheva comb. nov.</p><p>≡ Exidiopsis griseobrunnea K. Wells &amp; Raitviir, Eesti NSV Teaduste Akadeemia Toimetised 15: 206, 1966. Holotype. Russia. Tyumen Reg.: Yamal-Nenets Autonomous Dist., Krasnoselkup, Alnus fruticosa, 31 Jul 1964 Parmasto (TAAM 17048 *, studied) .</p><p>= Sclerotrema griseobrunneum (K. Wells &amp; Raitviir) Spirin &amp; Malysheva, Fungal Biology 121: 713, 2017.</p><p>Note.</p><p>For a description and photographs, see Malysheva and Spirin (2017). Ulocolla griseobrunnea differs from other Ulocolla spp. due to its effused, stereoid basidiomata and the presence of hymenial cystidia. The species was reported by Torkelsen (1972) from Norway. However, her specimens belong to Exidia plumbescens . So far, there have been no verified records of U. griseobrunnea from Europe.</p></div>	https://treatment.plazi.org/id/8699BED1430C53ED93914D76A9126576	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
E5BB709CCCDA5CE1AAF197E2D05FB308.text	E5BB709CCCDA5CE1AAF197E2D05FB308.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla orbiculata Spirin & Viner 2026	<div><p>Ulocolla orbiculata Spirin &amp; Viner sp. nov.</p><p>Figs 33 E, 36 D</p><p>Holotype.</p><p>Russia • Khabarovsk Reg.: Verkhnebureinskii Dist., <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=133.30898&amp;materialsCitation.latitude=50.49582" title="Search Plazi for locations around (long 133.30898/lat 50.49582)">Hegdy</a>, 50.49582 133.30898, Abies nephrolepis (hanging dead branch), 18 Aug 2014, Spirin 7487 * (H) .</p><p>Etymology.</p><p>Orbiculatus (Lat., adj.) – orbiculate.</p><p>Description.</p><p>Basidiomata annual, at first frustulate, later appressed-orbicular, up to 0.5 cm in diam., gradually fusing together and forming compound effused fructifications, up to 3 cm in the longest dimension, gelatinous, semitranslucent, up to 0.5 mm thick. Hymenial surface smooth, grayish-brown in fresh condition, brown or dark-brown and vernicose when dry. Margin sharply delimited and often slightly elevated, in mature basidiomata partly detaching.</p><p>Hyphal structure monomitic, hyphae clamped; subicular hyphae hyaline, variably thick-walled, subparallel, anastomosing, tightly agglutinated, hardly discernible, 1.5–3 μm in diam., subhymenial hyphae hyaline or yellowish, thin-walled or with a distinct wall, ascending or interwoven, frequently anastomosing, 1–3.5 μm in diam., occasionally inflated and then up to 5 μm in diam., basidia-bearing hyphae not differentiated. Crystals occasionally present, angular, scattered among hyphae, sometimes producing large concretions up to 25 μm in diam. Cystidia absent. Hyphidia thin-walled, with a thin-walled, hyaline, hyphoid stem, 1.5–3.5 μm in diam., and abundant, richly branched, hyaline or brownish apical outgrowths, 0.5–1.5 μm in diam. at the very apex, often forming a continuous layer up to 40 μm thick. Probasidia slightly tapering to nearly bullet-shaped, 9–19 × 3–8 μm. Basidia four-celled, ellipsoid-ovoid to subglobose, occasionally with a distinctly narrowed, stalk-like base, (10 –) 11–15 (– 15.5) × (7.8 –) 7.9–10.1 (– 11.2) μm (n = 20 / 1), thin-walled, embedded, sterigmata up to 20 × 2 μm. Basidiospores thin-walled, broadly to narrowly cylindrical, often distinctly curved, (9.8 –) 10.0–14.3 (– 15.7) × (3.9 –) 4.0–5.2 (– 5.3) μm (n = 21 / 1), L = 11.97, W = 4.45, Q = 2.69.</p><p>Remarks.</p><p>Ulocolla orbiculata is described here as the sister species of U. grisea . These species are phylogenetically closely related and anatomically very similar. However, their basidiomata differ considerably: U. grisea has widely effused (corticioid), adnate basidiomata while U. orbiculata possesses button-shaped basidiomata with an elevated margin reminiscent of many Exidia spp. which later fuse together in compound, partly detaching fruitbodies. Ulocolla orbiculata is so far known from two localities in Khabarovsk Region, Far East Russia. It was found on dead but still attached, corticated branches of Abies .</p></div>	https://treatment.plazi.org/id/E5BB709CCCDA5CE1AAF197E2D05FB308	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
ED3282CAE3D05C3AA7E4A05C445AE0F1.text	ED3282CAE3D05C3AA7E4A05C445AE0F1.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla pinicola (Peck) Spirin 2026	<div><p>Ulocolla pinicola (Peck) Spirin comb. nov.</p><p>Fig. 36 E</p><p>≡ Tremella pinicola Peck, Annual Report on the New York State Museum of Natural History 39: 44, 1886. Holotype. USA. New York: Saratoga Co., Day, coniferous branches, ‘ July’, Peck (NYS) .</p><p>= Exidia pinicola (Peck) Coker, Journal of the Elisha Mitchell Scientific Society 36: 150, 1920.</p><p>Description.</p><p>Basidiomata annual, at first cushion-shaped or adpressed-orbicular, narrowly or broadly attached, later cerebriform or almost foliaceous, up to 5 cm in diam. and 2 cm thick, gelatinous. Hymenial surface at first nearly smooth or uneven, then distinctly folded, amber-yellow to yellowish-brown, later reddish-brown, in dry condition brownish-black. Abhymenial surface smooth, concolourous with hymenial surface. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin- to distinctly thick-walled, interwoven or more rarely subparallel, anastomosing, 1–6.5 μm in diam., subhymenial hyphae hyaline to yellowish, thin- to distinctly thick-walled, predominantly ascending, 1.5–4 μm in diam., occasionally inflated up to 6–7 μm in diam., basidia-bearing hyphae 2–4 μm in diam. Cystidia absent. Hyphidia with a slightly thick-walled, hyaline or brownish, hyphoid or nodulose stem, 2–5 μm in diam., and hyaline or yellowish-brownish apical branches, 1–1.5 μm in diam., forming a continuous layer up to 40 μm thick. Probasidia clavate or tapering, 13–19 × 4–8 μm. Basidia thin-walled, four-celled, ellipsoid-ovoid, occasionally with a distinctly narrowed, stalk-like base, (13 –) 13.5–19 (– 21.5) × (8.4 –) 8.5–10.3 (– 11.0) μm (n = 20 / 2), sterigmata up to 30 × 1.2–1.5 μm. Basidiospores narrowly cylindrical to cylindrical, distinctly curved, (8.7 –) 9.2–13.2 (– 14.2) × (3.3 –) 3.7–5.1 (– 5.2) μm (n = 90 / 3), L = 10.46–11.67, W = 4.00–4.27, Q = 2.62–2.82.</p><p>Remarks.</p><p>Ulocolla pinicola is the North American relative of U. saccharina and U. subrepanda (Fig. 12). It inhabits various coniferous trees, mainly in the cold temperate and boreal regions. Morphologically, it is indiscernible from U. subrepanda from Eurasia and can be separated from the latter species based on DNA sequences and geographic distribution. In turn, U. saccharina from Europe possesses larger basidia and basidiospores than U. pinicola, and it is so far found only on Pinus spp.</p><p>This species was originally described from New York as Tremella pinicola (Peck 1886). Coker (1920) restudied the type and combined it in Exidia . He further concluded that E. pinicola is an older name for E. umbrinella from Europe (see description above). However, the spore measurements given by Coker (3.7–4 × 9.5–11.1 μm) rule out E. umbrinella and, in combination with macroscopic features, clearly point towards a member of the U. saccharina group.</p></div>	https://treatment.plazi.org/id/ED3282CAE3D05C3AA7E4A05C445AE0F1	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
36520E82065259A68431793084DD23ED.text	36520E82065259A68431793084DD23ED.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla saccharina (Fr.) Bref.	<div><p>Ulocolla saccharina (Fr.) Bref., Untersuchungen aus dem Gesammtgebiete der Mykologie 7: 95, 1888</p><p>Figs 33 F, 36 F, 38</p><p>≡ Exidia saccharina Fr., Systema Mycologicum 2: 225, 1822. Neotype (selected here, MBT 10031462). Finland. Uusimaa: Helsinki, Koskela, Pinus sylvestris, 14 Jun 2014, Miettinen 18284.1 * (H) .</p><p>= Tremella spiculosa var. saccharina Alb. &amp; Schwein., Conspectus Fungorum in Lusatiae Superioris: 302, 1805.</p><p>= Exidia subsaccharina F. Wu, Rivoire, Tohtirjap &amp; Y. C. Dai, Frontiers in Microbiology 13 (1080290): 7, 2023. Holotype. France. Rhône: Chaussan, Pinus sylvestris, 10 Aug 2008, Dai 22187 * (BJFC 36778) .</p><p>Description.</p><p>Basidiomata annual, at first cushion-shaped or adpressed-orbicular, narrowly or broadly attached, later cerebriform, up to 5 cm in diam., finally often fusing together and reaching 20 cm in the longest dimension, up to 2 cm thick, gelatinous. Hymenial surface at first nearly smooth or uneven, then distinctly folded, occasionally covered by rather regularly arranged spine-like projections up to 0.2 mm long, amber-yellow to yellowish-brown, later reddish-brown, in dry condition brownish-black. Abhymenial surface smooth, concolourous with hymenial surface. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin- to slightly or rarely distinctly thick-walled, predominantly interwoven, spaced, anastomosing, 1–6.5 μm in diam., subhymenial hyphae hyaline to yellowish, thin- to slightly thick-walled, ascending or interwoven, 2–5 (7) μm in diam., basidia-bearing hyphae 2–6 μm in diam. Cystidia absent. Hyphidia with a thin- or slightly thick-walled, yellowish or brownish, hyphoid or nodulose stem, 2–9 μm in diam., and hyaline or yellowish-brownish apical branches, 1–2 μm in diam., forming a continuous layer up to 50 μm thick. Probasidia broadly to narrowly clavate, 13–20 × 4–8.5 μm. Basidia thin-walled, four-celled, ellipsoid-ovoid, some with a distinctly narrowed, stalk-like base, (14.5 –) 15–22.5 (– 23) × (9.1 –) 9.2–13.0 (– 13.2) μm (n = 60 / 6), sterigmata up to 30 × 2–2.5 μm. Basidiospores narrowly cylindrical to allantoid, more rarely cylindrical, distinctly curved, (10.1 –) 10.2–17.7 (– 18.1) × (3.7 –) 3.8–5.8 (– 6.1) μm (n = 180 / 6), L = 13.49–15.25, W = 4.24–5.00, Q = 2.98–3.24.</p><p>Remarks.</p><p>Ulocolla saccharina is distributed in temperate and hemiboreal forests of Europe and seemingly restricted to wood remains of Pinus spp. Substantial basidiomata with distinctly a plicate or reticulate hymenophore often bearing papillose projections, as well as large basidia and long basidiospores help to separate it from the closely related U. subrepanda . The latter species has a more northern distribution and occurs on a larger set of coniferous hosts (see below).</p><p>This species was introduced by Fries (1822) as E. saccharina although his name and, at some important parts, description referred to that of ‘ Tremella spiculosa γγ saccharina ’ by Albertini and Schweinitz (1805). No authentic material is extant from the latter authors or Fries. Albertini and Schweinitz (ibid.) described T. spiculosa var. saccharina as producing large, brown, plicate-undulate basidiomata on freshly cut Pinus logs and having a papillose hymenial surface. The latter feature was also emphasized by Fries (1822). He observed E. saccharina inhabiting logs of Pinus and Picea (given as Abies) in Sweden. From his indication of the host trees, we can suggest that Fries’ concept of E. saccharina was mixed, i. e. it also covered the second European species from the U. saccharina complex reintroduced below as U. subrepanda . However, the hymenial surface of U. subrepanda can hardly be described as papillose. Poorly developed sharp warts are present only occasionally in senescent basidiomata of the latter species and they are visible only under magnification. On the contrary, hymenial projections of U. saccharina, if present, are usually detectable with the naked eye. This trait allows us to suggest that the pine-dwelling collections (i. e. those ones belonging to U. saccharina in the present sense) were the main source of the species introduction by Fries. The color photo of the type specimen of E. subsaccharina published by Gruhn et al. (2024) shows typical specimen of U. saccharina with a papillose hymenial surface. Based on morphological traits and sequences of E. subsaccharina, we place it as a synonym of U. saccharina . See further remarks under U. pinicola and U. subrepanda .</p></div>	https://treatment.plazi.org/id/36520E82065259A68431793084DD23ED	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
6EBF40BD052951099496856489992C47.text	6EBF40BD052951099496856489992C47.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ulocolla subrepanda (P. Karst.) Spirin 2026	<div><p>Ulocolla subrepanda (P. Karst.) Spirin comb. nov.</p><p>Figs 33 G, 36 G</p><p>≡ Exidia albida ssp. subrepanda P. Karst., Meddelanden af Societas pro Fauna et Flora Fennica 18: 73, 1891. Lectotype (selected by Spirin et al. 2018: 7). Finland. Etelä-Häme: Tammela, Mustiala, Picea abies, 18 Nov 1890, Karsten 2143 (H 6061344, studied) .</p><p>= Exidia subrepanda (P. Karst.) Oudemans, Enumeratio Systematica Fungorum 1: 398, 1919.</p><p>Description.</p><p>Basidiomata annual, at first cushion-shaped or adpressed-orbicular, narrowly or broadly attached, later cerebriform or almost foliaceous, up to 6 cm in diam. and 2 cm thick, gelatinous. Hymenial surface at first nearly smooth or uneven, then distinctly folded, occasionally covered by poorly visible densely arranged warts, amber-yellow to yellowish-brown, later reddish-brown, in older specimens fading to pale yellow, in dry condition brownish-black. Abhymenial surface smooth, concolourous with hymenial surface. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate.</p><p>Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin- to distinctly thick-walled (walls often strongly gelatinized), interwoven, anastomosing, 1–5 μm in diam., subhymenial hyphae hyaline to yellowish, thin- to distinctly thick-walled, ascending or interwoven, 1–5 μm in diam., basidia-bearing hyphae 2–4 μm in diam. Cystidia absent. Hyphidia with a distinctly thick-walled, brownish or brown, hyphoid or nodulose (occasionally almost moniliform) stem, 2–6 μm in diam., and yellowish-brownish apical branches, 1–2 μm in diam., forming a continuous layer up to 40 μm thick. Probasidia clavate or tapering, 14–18 × 5–7 μm. Basidia thin- or slightly thick-walled, four-celled, ellipsoid-ovoid to narrowly ovoid, some with a distinctly narrowed, stalk-like base, occasionally obliquely septate, (13 –) 13.5–20 (– 20.5) × (7.2 –) 7.3–10.4 (– 10.9) μm (n = 70 / 7), sterigmata up to 15 × 1.2–1.5 μm. Basidiospores narrowly cylindrical to cylindrical, distinctly curved, (8.1 –) 8.2–13.3 (– 14.2) × (3.2 –) 3.3–5.4 (– 5.7) μm (n = 240 / 8), L = 9.96–11.33, W = 3.91–4.85, Q = 2.35–2.81.</p><p>Remarks.</p><p>Ulocolla subrepanda is widely distributed in the cold temperate and boreal ecosystems of Eurasia where it inhabits wood (mainly freshly fallen logs and thick branches) of various coniferous trees. Morphologically and phylogenetically, it is closely related to U. saccharina from Europe and U. pinicola from North America. It differs from U. saccharina in having smaller basidia and basidiospores. The basidiomata of U. subrepanda are also usually smaller than those of U. saccharina, and they are devoid of easily detectable hymenial projections. We could not find any reliable morphological traits separating U. subrepanda and U. pinicola . However, these species show clear differences in ITS sequences and they are distributed in different geographic areas.</p><p>This species was first introduced as a variety of Exidia albida sensu auct. (Karsten 1891) and then raised to the species rank in the genus Exidia (Oudemans 1919) . The type specimen was collected from Picea abies . It is completely sterile; however, the host tree and rather small basidia preclude U. saccharina s. str. (see above).</p></div>	https://treatment.plazi.org/id/6EBF40BD052951099496856489992C47	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Spirin, Viacheslav;Malysheva, Vera;Schoutteten, Nathan;Savchenko, Anton;Rivoire, Bernard;Olsson, Jan;Læssøe, Thomas;Ryvarden, Leif;Grootmyers, Django;Kulju, Matti;Vlasák, Josef;Vignale, María Victoria;Viner, Ilya	Spirin, Viacheslav, Malysheva, Vera, Schoutteten, Nathan, Savchenko, Anton, Rivoire, Bernard, Olsson, Jan, Læssøe, Thomas, Ryvarden, Leif, Grootmyers, Django, Kulju, Matti, Vlasák, Josef, Vignale, María Victoria, Viner, Ilya (2026): Exidia and Exidiopsis (Auriculariales, Basidiomycota): a reconsideration. IMA Fungus 17: e 189042, DOI: 10.3897/imafungus.17.189042
