taxonID	type	description	language	source
03AC8791FFB25916FF7DFA5E1283F9A4.taxon	description	= Pluteus phaeoleucus E. Horak, Bulletin du Jardin Botanique National de Belgique 47 (1 – 2): 89 (1977)	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFB25916FF7DFA5E1283F9A4.taxon	diagnosis	Diagnosis: — Based on material from Aneityum, P. albostipitatus is characterized macroscopically by a gray-brown, variably fibrillose, centrally punctate pileus and a white stipe. Microscopically it is characterized by subglobose to broadly ellipsoid spores (8.1 × 6.2 µm), clavate cheilocystidia, fusoid, thin to thick-walled pleurocystidia with 2 – 6 apical hooks, a cutis pileipellis, and the absence of caulocystidia. Description: — Pileus 35 – 37.5 mm diam., plano-convex to broadly plano-convex, margin entire or splitting; surface somewhat pearlescent, dry, disc pustulate or warted with agglutinated hairs, variably appressed-fibrillose; disc gray-brown (56 E 3 – 4), fibrils gray (5 DE 2 – 3) towards margin, underlying surface pallid gray. Context thin, pallid gray. Lamellae free, close with 2 tiers of lamellulae, moderately broad (3 – 4 mm), white-gray to pink-gray with brown tones (6 – 7 B 2 – 3), margin paler, slightly eroded. Stipe 32 – 47 × 2.5 – 3 mm, central, terete, cylindrical above a subbulbous base (4 – 6 mm), solid; surface pearlescent, dry, silky, pallid white-gray with brown tones towards base and where handled, context white. Odor indistinct. Taste not observed. Basidiospores (5 –) 6 – 11 (– 13) × 5 – 8 (– 9) µm [x mr = 7.41 – 8.88 × 6.12 – 6.3 µm, x mm = 8.15 ± 1.0 × 6.21 ± 0.62 µm, Q = 1 – 1.6 (– 2.0), Q mr = 1.21 – 1.42, Q mm = 1.31 ± 0.25, n = 50, s = 2], subglobose to broadly ellipsoid, seldom globose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 15 – 35 × 6 – 11 µm, subclavate to cylindro-clavate, 4 - spored, hyaline, thin-walled, sterigmata 2 – 5 × 0.5 – 1 µm. Basidioles 11 – 25 × 4 – 10 µm, clavate to subclavate, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia 24 – 60 × 8 – 22 µm, clavate to subclavate or fusoid-ventricose to sphaeropedunculate, obtuse or subcapitate to umbonate, hyaline, thin-walled. Pleurocystidia 53 – 110 × 6 – 22 µm, common, fusiform to fusoid-ventricose or seldom utriform to broadly clavate, obtuse to truncate without outgrowths, with 2 – 4 clefts, or infrequently corniculate with 2 – 6 whole or bifid, blunt, recurved poorly-developed apical hooks, rarely asymmetrical, hyaline, some with a guttule, thin to thick-walled (up to 2 µm thick) often thinning towards the base. Pileipellis a cutis of repent hyphae, composed of hyaline or pale to dark brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled, cylindrical hyphae, 4 – 20 (– 25) µm diam.; terminal elements 35 – 111 × 7 – 22 µm, suberect to erect towards disc and repent elsewhere, cylindrical to clavate, obtuse or infrequently subcapitate. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical to inflated hyphae, 3 – 28 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 20 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 20 (– 25) μm diam .. Caulocystidia absent. Clamp connections present sometimes in stipitipellis tissue, and absent in all other tissues. Habitat and known distribution: — Solitary on decaying wood in subtropical coastal scrub, mangrove forest, secondary littoral forest, and mixed-use agro tree garden containing Annona muricata (Annonaceae), Artocarpus altillis (Moraceae), Bruguiera gymnorhiza (Rhizophoraceae), Cocos nucifera (Arecaceae), Macaranga tanarius (Euphorbiaceae), Magnifera indica (Anacardiaceae), Musa spp. (Musaceae), and Syzygium richii (Myrtaceae) or montane primary broadleaf- Araucariaceae / Podocarpaceae rainforest containing Agathis macrophylla (Araucariaceae), Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Dendrocnide latifolia (Urticaceae), Ficus septica (Moraceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Geissois denhamii (Cunoniaceae), Hernandia moerenhoutiana (Hernandiaceae), Macaranga dioica (Euphorbiaceae), Podocarpus vanuatuensis (Podocarpaceae), Polyscias cissondendron (Araliaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Aneityum). Also known from Africa (D. R. Congo, São Tomé), Asia (Thailand, Vietnam), Caribbean (Martinique, Trinidad), South America (Argentina, Bolivia, Brazil, French Guiana, Galapagos Islands), and North America (United States, Florida, Indiana). Material examined: — VANUATU. Tafea Province: Aneityum, Anloulanelcau area, trail through mixed forest to transect 11, 20 ° 13.066 ′ S, 169 ° 47.406 ′ E, elev. 188 m, 29 July 2017, coll. B. A. Perry, BAP 930 (HAY); Aneityum, along trail from Anelgauhat towards Umej, 20 ° 14.202 ′ S, 169 ° 48.203 ′ E, elev. 26 m, 7 August 2017, coll. M. C. Aime, BAP 968 (HAY). Notes: — A survey of multiple descriptions of P. albostipitatus (Dennis) Singer (1958: 240) reveals a morphologically cryptic species with wide macroscopic and microscopic variation, as also acknowledged by previous authors (Desjardin & Perry 2018, Menolli & Capelari 2010, Menolli et al. 2015 a). Originally described from Trinidad as P. spilopus var. albostipitatus Dennis (1953: 195) before being elevated to species rank by Singer (1958), the species was initially placed in sect. Hispidoderma due to early collections generally displaying thin-walled pleurocystidia with truncate, hookless apices (Dennis 1953). Singer reported small apical outgrowths on pleurocystidia from Argentinean material, and both he and Pegler suspected that this atypical shape had an intermediate link to metuloid cystidia found in species of sect. Pluteus (Pegler 1983 a, Singer 1958). Phylogenetic studies have confirmed the position of P. albostipitatus within sect. Pluteus as part of the salicinus / albostipitatus clade recognized by Justo et al. (2011 b), which includes other species containing thin-walled pleurocystidia with poorly developed apical hooks that are considered atypical for the section (Justo et al. 2011 b, Menolli & Capelari 2010). Recent descriptions of this species by Menolli et al. (2015 a) and Desjardin and Perry (2018) display the extent of microcharacter variation within the species, and provide additional instances of pleurocystidia with poorly developed apical outgrowths and thin to thick walls similar to those seen in the Vanuatu specimens. Based on multiple descriptions, the current concept of P. albostipitatus defines the pileus as morphologically variable, with the surface ranging from densely appressed-fibrillose to completely smooth and glabrous (Justo et al. 2011 b, Menolli et al. 2015 a, Singer 1956). Desjardin and Perry (2018) reported the pileus disc being appressed-fibrillose, but glabrous to subglabrous elsewhere, and Singer noted collections appearing subglabrous when wet, but typically “ when fresh and dry more or less distinctly radially fibrillose with innate fibrils ” (Singer 1956). Referring to a photo of Desjardin and Perry’s São Tomé material (Fig. 7, 2018), the material appears older and wet, possibly similar to Singer’s observations, and is an example of the influence of environmental factors on superficial appearance during collecting. The material from Aneityum appears as appressed-fibrillose with shades of gray to grayish brown, matching descriptions from multiple authors (Dennis 1953, Horak 1964, Menolli & Capelari 2010, Menolli et al. 2015 a, Singer 1956). Species such as P. phaeoleucus Horak (1976: 89) from the D. R. Congo (Horak 1976) and P. densifibrillosus Menolli & Capelari (2010: 698) from Brazil (Menolli & Capelari 2010), that are recognized as synonymous with P. albostipitatus (Menolli et al. 2015 a) were described with a non-striate pileus, similar to the Vanuatu material. In contrast, other authors have described the pileus as being striate to sulcate (Dennis 1953, Desjardin & Perry 2018, Horak & Heinemann 1978, Menolli et al. 2010, Pegler 1983 a, Singer 1956). All prior mentioned accounts also describe the pileus center as punctate, nippled or some variation, and this occurs in the Aneityum material.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFB25916FF7DFA5E1283F9A4.taxon	description	Considering the extensive morphology within the P. albostipitatus complex, further investigation of delimiting characters is necessary, including comparisons to specimens of P. septocystidiatus. Based on the description and photo of the Korean holotype of P. septocystidiatus (Fig. 1, Ševčíková et al. 2014), the dark brown, striate, and centrally rugulose characters of the pileus (perhaps comparable to punctate / warted / nippled) seem to be shared characters within the observed range of comprehensive descriptions of P. albostipitatus. Previous authors have acknowledged other taxonomically useful characters when distinguishing species in sect. Pluteus including the presence of clamp connections in the pileipellis and stipitipellis tissue (Justo et al. 2014, Singer 1956). Molecular studies of sect. Pluteus have also found the use of tef 1 gene data to provide better phylogenetic resolution compared to ITS alone (Justo et al. 2014, Menolli et al. 2014). Further study and intensive re-examination utilizing these characters and additional molecular markers could provide better resolution in the P. albostipitatus complex. For the sake of this study, identification of the Aneityum material better fits the wide range of morphological variation in P. albostipitatus. Pluteus albostipitatus appears to be a pantropical species known to occur throughout the subtropical and tropical Americas from Florida, U. S. A., through the Caribbean to Brazil and the Galapagos Islands, and tropical mainland Africa and its coastal islands. Interestingly, specimens of P. septocystidiatus have both a temperate distribution in the eastern to midwestern U. S. A. and South Korea and a subtropical to tropical occurrence in Florida, U. S. A., Vietnam, and Thailand. Although the Aneityum material is phylogenetically closer to P. septocystidiatus, the absence of septate pleurocystidia would separate them, but this septate character could just be an extension of the morphological variation within P. albostipitatus pending future studies.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFAE5914FF7DF9601443FC98.taxon	description	≡ Pluteus cervinus var. petasatus (Fr.) Fr., Hymenomycetes europaei: 186 (1874) Reported heterotypic synonyms:	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFAE5914FF7DF9601443FC98.taxon	diagnosis	Diagnosis: — Based on material collected from Tafea Province, P. petasatus is characterized by a dry or viscid, ash brown fibrillose pileus and a white with sparse ash brown fibrils stipe with a subbulbous base. Basidiome variants include some that are white overall, as in JAD 45, or have ash brown floccules at the disc, as in JAD 47. Microscopic characters include broadly ellipsoid spores (7.0 × 4.6 µm), sparse clavate cheilocystidia, fusiform, thick-walled pleurocystidia with 2 – 4 apical hooks, similar thin-walled intermediate pleurocystidia, an ixo-cutis pileipellis, an absence of caulocystidia, and an absence of clamp connections. Description: — Pileus 35 – 80 mm diam., broadly convex, expanding to plano-convex, with or without a broad umbo, with or without a slight central depression; surface dull, dry to moist, the disc glabrous, appressed fibrillose or flocculose, glabrous towards the margin, cream, white to isabelline (oac 815 – oac 816) or pale pink (oac 675 – oac 676), fibrils if present ash brown (oac 737 – oac 739), floccules if present dark ash brown (oac 735 – oac 737). Context 2 – 4 mm thick, white. Lamellae free, crowded with many tiers of lamellulae, thin (1 – 2 mm thick), pale pink (oac 682 – oac 683 or oac 695 – oac 697), edges concolorous. Stipe 50 – 90 mm × 5 – 15 mm, central, terete, cylindrical above a subbulbous base, solid; surface dull, dry, glabrous to sparsely fibrous, white overall or with ash brown (oac 737 – oac 739) fibrils that tend to become denser towards the base, context white. Odor indistinct. Taste indistinct. Basidiospores 6 – 9 (– 10) × 4 – 6 (– 8) µm [x mr = 6.18 – 7.52 × 4.18 – 4.77 µm, x mm = 6.95 ± 0.69 × 4.56 ± 0.33 µm, Q = 1.16 – 2.25, Q mr = 1.48 – 1.59, Q mm = 1.53 ± 0.59, n = 50, s = 3], broadly ellipsoid to subellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 16 – 26 × 5 – 10 µm, clavate, 4 - spored, hyaline, thin-walled, sterigmata 2 – 5 × 0.5 – 1 µm. Basidioles 12 – 22 × 5 – 10 µm, clavate to subcylindrical, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia 18 – 71 × 8 – 35 µm, sparse, infrequently forming a well-developed strip on lamellar edge, clavate to narrowly clavate or sphaeropedunculate, obtuse, hyaline, thin-walled. Pleurocystidia; primary pleurocystidia 60 – 92 × 12 – 24 µm, fusiform to narrowly utriform, cornuate with 2 – 4 whole, straight to recurved poorly or well-developed apical hooks, some acute, occasionally with 1 – 3 lateral hooks, hyaline, evenly thick-walled (up to 2.5 µm thick); intermediate pleurocystidia 38 – 61 × 8 – 13 µm, similar to primary pleurocystidia but smaller, fusiform to fusoid, acute or occasionally with 2 – 3 whole, recurved apical hooks, often with 1 – 3 lateral excrescences, hyaline, thin to thick-walled (up to 2 µm thick). Pileipellis an ixo-cutis of repent hyphae, embedded in a gelatinous matrix or a cutis with an external gelatinous layer of narrow hyphae, 2 – 6 µm diam., composed of hyaline or containing brown plasmatic pigment, non-incrusted, gelatinized or not, thin-walled, cylindrical hyphae, 4 – 18 µm diam.; terminal cells 30 – 150 × 7 – 20 µm, repent to erect towards disc, clavate, obtuse, sometimes strongly tapering, seldom with median constriction. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical to inflated hyphae, 9 – 25 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 4 – 13 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 5 – 29 µm diam .. Caulocystidia absent. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary on decaying wood in subtropical coastal scrub, mangrove forest, secondary littoral forest, and lowland mixed-use agro tree garden containing Annona muricata (Annonaceae), Artocarpus altillis (Moraceae), Barringtonia asiatica (Lecythidaceae), Bruguiera gymnorhiza (Rhizophoraceae), Cocos nucifera (Arecaceae), Cordia dichotoma (Boraginaceae), Euodia hortensis (Rutaceae), Leucaena leucocephala (Fabaceae), Macaranga dioica (Euphorbiaceae), Macaranga tanarius (Euphorbiaceae), Magnifera indica (Anacardiaceae), Musa spp. (Musaceae), and Syzygium richii (Myrtaceae), Vanuatu (Aneityum, Tanna). Also known from Asia (Japan, Mongolia, Russia), Europe (Spain), North America (Canada, Mexico, United States), South America (Argentina, Paraguay), and Papua New Guinea. Material examined: — VANUATU. Tafea Province: Aneityum, along trail from Anelgauhat towards Umej, 20 ˚ 14.208 ′ S, 169 ˚ 47.940 ′ E, elev. 26 m, 4 August 2017, coll. M. J. Balick, JAD 45 (HAY); same location 4 August 2017, coll. J. A. del Rosario & M. C. Aime, JAD 47 (HAY); Tanna, Port Resolution, trail between Tanna Horizon Bungalow and Ireupow, 19 ° 31.310 ′ S, 169 ° 30.365 ′ E, elev. 7 m, 16 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 298 (HAY). Notes: — Pluteus petasatus is a species with one of the broadest known distributions within the genus as it has been recorded throughout Eurasia and North America, extending into the Southern Hemisphere. Justo et al. (2014) determined that P. petasatus produces basidiomes with morphologically variable pilei, ranging from dry to viscid, glabrous to variably fibrillose, and having color within a wide spectrum of cream, white, isabelline (pale grayyellow or parchment-colored), and brown to dark gray. Based on molecular evidence and extensive examination of microscopic characters, Justo et al. (2014) proposed multiple species analogous to P. petasatus. The material collected from Aneityum and Tanna fits well within the range of macromorphological characters and consistent microscopic characters under the concept of P. petasatus as defined by Justo et al. (2014). Phylogenetic analysis based on ITS data (Fig. 1 b) places the Tafean material with collections from Papua New Guinea and Japan (originally identified as P. magnus McClatchie (1897: 383 )) in a well-supported subclade (BS 90 %, PP 0.99) within a larger clade of a global sampling from material identified as P. petasatus. Pluteus magnus had been proposed as a synonym of P. petasatus, despite the absence of molecular data, due to the holotype having identical microcharacters (Justo et al. 2014). A comprehensive comparison of previous descriptions of P. magnus to the Tafean material reveals identical morphology, except for the Vanuatu specimen’s ixo-cutis pileipellis, which has not been observed in previous accounts (Banerjee & Sundberg 1993, McClatchie 1897, Singer 1956, Takehashi & Kasuya 2009). Interestingly, the subclade contains collections distributed along the Pacific Ocean from East Asia to Australasia. Collections from Canada (JN 021081) and the U. S. A. (JX 857453) form a weakly supported subclade (BS 59 %, PP 0.94) sister to the preceding subclade, however this is unsupported. The specimen from the U. S. A. was collected from southern California in the same locality as the type specimen of P. magnus and may possibly serve as topotypical material. Whether or not either of these subclades are representative of P. magnus, and if it should be recognized as a separate species, requires further investigation. Current knowledge indicates that P. petasatus is a widely distributed species occurring in various environments, from disturbed habitats to natural and undisturbed forest, and in drastically different climates, from subtropical to tropical and Mediterranean to temperate. The Vanuatu collections were frequently collected in disturbed coastal forests and according to available records from GenBank, the Papua New Guinea material was collected on the University of Goroka campus. Both the Japanese and Californian collections appear to have been found in urban areas. In these instances, a possible explanation for such a wide distribution may be due to anthropogenic movement of fungal propagules or substrate.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFA9591EFF7DFF5714C2FBE5.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Tanna, Numdretum River, 19 ° 38.246 ′ S, 169 ° 25.237 ′ E, elev. 145 m, 4 December 2018, coll. J. A. del Rosario, JAD 189 (HAY). Etymology: — Refers to the Vanuatu islands where the holotype was collected. Diagnosis: — Pluteus vanuatuensis from Tafea is distinguished by a grayish brown to hazel appressed-fibrillose, black floccose-pustulate disc, hygrophanous and sulcate pileus, and a white stipe with pale brown minute streaks and a bulbous base. All tissues bruise a faint bluish gray. Microcharacters include subglobose basidiospores (7.3 × 6.6 µm), clavate cheilocystidia, fusoid, thick-walled pleurocystidia with 2 – 5 apical hooks, similar but smaller intermediate pleurocystidia, a cutis pileipellis with erect clavate terminal elements at the disc, absent caulocystidia, and the presence of clamp connections in all tissue. Description: — Pileus 25 – 70 mm diam., hemispherical to plano-convex with a slight centrally depressed umbo; surface dull to pellucid-striate up to half-way from margin, hygrophanous, finely appressed-fibrillose to subglabrous, disc floccose-pustulate; floccules / pustules / fibrils dark chocolate brown (oac 639 – oac 641) to brown-black, underlying surface dull gray-brown (oac 730 – oac 736 / oac 720 – oac 722) turning pallid brown (oac 751 – oac 753) to pale hazel (oac 646 – 648) towards margin. Context up to 1.5 mm thick, pallid gray-brown turning faintly bluish gray when exposed. Lamellae free, moderately close with 3 tiers of lamellulae, thin (up to 1 mm thick), light pink (oac 632 – oac 634 / oac 696 – oac 697). Stipe 40 – 60 × 3 – 4 mm, central, terete, cylindrical above a subbulbous to bulbous base, hollow; surface pearlescent, dry, silky, white to off-white without or infrequently with tannish brown (oac 672 – oac 675) tones mid-way towards the base, occasionally with bluish gray tones at the base, context white. Tissues turning bluish gray when disrupted or handled. Odor indistinct. Taste indistinct. Basidiospores (5 –) 6 – 8 (– 9) × (5 –) 6 – 7 (– 8) µm [x mr = 6.98 – 7.56 × 5.98 – 6.94 µm, x mm = 7.26 ± 0.23 × 6.49 ± 0.35 µm, Q = 1 – 1.5, Q mr = 1.04 – 1.18, Q mm = 1.12 ± 0.04, n = 50, s = 6], globose to subglobose, rarely broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia (15 –) 18 – 34 × 6 – 8 µm, clavate, 4 - spored or rarely 2 - spored, hyaline, thin-walled, sterigmata 2 – 3 × 0.5 – 1 µm. Basidioles 16 – 35 × 6 – 10 µm, clavate, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia 30 – 75 × (8 –) 15 – 24 µm, clavate or seldom sphaeropedunculate or utriform, obtuse or seldom subcapitate, hyaline, thin-walled. Pleurocystidia; primary pleurocystidia 50 – 102 × 12 – 25 µm, fusoid to narrowly lageniform, apex variable, cornuate or corniculate with 2 – 4 (– 5) whole to bifid, straight or recurved poorly or well-developed apical hooks, bifid frequency varying among specimens with acute, cornuate or corniculate arms, most with a guttule, rarely asymmetrical, hyaline, thin to thick-walled (up to 2 µm thick); intermediate pleurocystidia 33 – 66 × 11 – 25 µm, fusoid to lageniform or seldom utriform, obtuse, acute or corniculate to rarely cornuate with 1 – 4 whole, blunt, straight to recurved poorly developed apical hooks, with a guttule, hyaline, thin to thick-walled. Pileipellis a cutis of repent hyphae, composed of grayish brown plasmatic pigment or hyaline, non-incrusted, non-gelatinous, thin-walled, cylindrical hyphae, 5 – 20 µm diam.; terminal elements 45 – 135 (– 180) × 11 – 18 µm, in erect fascicles at the disc, clavate or filiform, obtuse, rarely strongly tapering or subcapitate, rarely entirely nodulose (one collection), hyaline or with grayish brown plasmatic pigment, thin-walled. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical to inflated hyphae, 7 – 25 (– 35) µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 5 – 22 µm diam .. Stipitipellis a cutis, composed of hyaline or sometimes with grayish brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 18 µm diam .. Caulocystidia absent. Clamp connections present in all tissues examined. Habitat and known distribution: — Gregarious to solitary on decaying wood in subtropical lowland mixed-use agro tree garden and secondary broadleaf rainforest containing Bischofia javanica (Phyllanthaceae), Burckella obovata (Sapotaceae), Claoxylon gillisonii (Euphorbiaceae), Dendrocnide latifolia (Urticaceae), Didymocheton spp. (Meliaceae), Ficus spp. (Moraceae), Garcinia pseudoguttifera (Clusiaceae), Homolanthus nutans (Euphorbiaceae), Macaranga dioica (Euphorbiaceae), and Syzygium nomoa (Myrtaceae), Vanuatu (Aneityum, Tanna). Material examined: — VANUATU. Tafea Province: Tanna, Numdretum River, 19 ° 38.440 ′ S, 169 ° 25.385 ′ E, elev. 131 m, 29 August 2018, coll. J. A. del Rosario, JAD 160 (HAY); Tanna, Yanemarei, 19 ° 38.511 ′ S, 169 ° 25.616 ′ E, elev. 94 m, 30 August 2018, coll. J. A. del Rosario, JAD 169 (HAY); Tanna, Numdretum River, 19 ° 38.246 ′ S, 169 ° 25.237 ′ E, elev. 145 m, 4 December 2018, coll. J. A. del Rosario, JAD 189 (HAY); Tanna, Tangahuruti, 19 ° 38.809 ′ S, 169 ° 26.382 ′ E, elev. 66 m, 6 December 2018, coll. J. A. del Rosario, JAD 215 (HAY); Aneityum, Nathaway, 20 ° 14.245 ′ S, 169 ° 48.177 ′ E, elev. 0 m, 10 December 2018, coll. J. A. del Rosario, JAD 229 (HAY); Tanna, Yakuwan, 19 ° 32.230 ′ S, 169 ° 28.911 ′ E, elev. 84 m, 15 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 286 (HAY). Notes: — The distinctive bluish gray bruising of disrupted tissue from this species requires comparison to similar species, such as P. salicinus (Persoon) Kummer (1871: 99), P. saupei Justo & Minnis (2011: 475), and P. americanus (Banerjee & Sunderberg) Justo, E. F. Malysheva & Minnis (2014: 180). The Eurasian P. salicinus differs in having a grayer pileus, smaller ellipsoid spores, less versiform pleurocystidia with developed apical hooks, intermediate pleurocystidia lacking apical hooks, and more clavate cheilocystidia (Justo et al. 2014). Known only from the state of Illinois in the U. S. A., P. saupei shares the outward appearance of P. vanuatuensis, but microscopically differs by having slightly larger ellipsoid spores, pleurocystidia with poorly developed hooks, and more lageniform cheilocystidia with elongated apices (Justo et al. 2011 b). Pluteus americanus was originally described as a variety of P. salicinus before being elevated to species rank based on molecular data and geographic distinction by being known from the eastern United States and Russian Far East (Banerjee & Sundberg 1993, Justo et al. 2014). Pluteus americanus is also superficially very similar to the Vanuatu specimen, but differs with its lighter-colored pileus, more ellipsoid spores, less apically versiform pleurocystidia, non-apically hooked intermediate pleurocystidia, and the absence of utriform or umbonate cheilocystidia (Justo et al. 2014). Some additional tropical species share similarities to P. vanuatuensis, but fundamentally differ in lacking blue-gray bruising. From Papua New Guinea, P. kobayasii Hongo (1976: 100) is one of the few species of Pluteus known from Vanuatu’s neighbouring region. Although this taxon has a similarly colored pileus and contains clamp connections in the hyphal tissue, it differs by lacking a floccose disc or a pellucid-striate margin, is slightly smaller in stature, has fusoid thick-walled cheilocystidia, and lacks apically variable pleurocystidia (Hongo 1976). The type of P. saupei was originally identified as a specimen of P. salicinus, and the material from both species was used to demonstrate the presence of the psychotropic compound psilocybin for the first time in a species of Pluteus (Saupe 1981). Psilocybin expression and similar blue bruising reactions arose independently in multiple lineages throughout the evolutionary history of fungi (Guzmán et al. 1998). These same blue, gray, or sometimes green-toned bruising reactions have been shown to originate at least twice in the evolution of the genus Pluteus, as this character is known to occur in P. cyanopus Quélet (1883: 391) and P. phaeocyanopus Minnis & Sunderberg (2010: 44) of sect. Celluloderma, and members of the P. glaucotinctus Horak (1976: 88) complex, which falls in the salicinus / albostipitatus clade recognized by Justo et al. (2011 b) (Justo et al. 2014, Minnis & Sundberg 2010). Currently, the presence of psilocybin has only been confirmed in certain species within the salicinus / albostipitatus clade, and not all members, such as the aforementioned P. albostipitatus, have been observed to exhibit a similar bruising reaction (Menolli et al. 2014). Based on ITS molecular data (Fig. 1 c), P. vanuatuensis is phylogenetically placed within the salicinus / albostipitatus clade recognized by Justo et al. (2011 b). This relationship to other members of this group known to display a blue bruising reaction and produce psilocybin or allied compounds raises the question if the compound is produced by P. vanuatuensis as well. Among all the specimens made during this study, P. vanuatuensis is represented by the highest number of collections, and observations conclude that it is a morphologically variable species. Pleurocystidia display a wide variety of apical ornamentation without a distinct dominant type, ranging from well to poorly developed cornuate, corniculate, bifid, or obtuse. Phylogenetic analysis (Fig. 1 c) places these collections in a well-supported clade with two distinct lineages: one is strongly supported (BS 100 %, PP 1.0) containing collections JAD 169, JAD 189, and JAD 229, another is moderately supported (BS 83 %, PP 0.99) containing collections JAD 160, JAD 215, JAD 159, and a Vietnamese specimen of P. sp. 1 (OQ 732732). Comparison of the Vanuatu specimens with the description of the Vietnamese specimen (Malysheva et al. 2023) indicates that the collections of these two clades show no discernible morphological differences to clearly separate them, except collection JAD 159 which has enough different morphological features to warrant treatment as a separate taxonomic unit discussed in the following section. A pairwise analysis of the overlapping region of JAD 159 against both lineages showed a 90.37 – 90.75 % similarity when indels were included and a 93.06 – 94.03 % difference when indels are excluded. Unfortunately we were not able to produce ITS data for JAD 286 due to a high number of indels, but tef 1 data was successfully generated. The identity of JAD 286 as P. vanuatuensis is confirmed based on analysis of tef 1 data (Fig. 6 c) and morphological similarity. One collection, JAD 285, is positioned outside of this clade in both analyses for the wider sampled ITS dataset, but this is weakly supported (ML 59 %, PP 0.66). The phylogenetic affinity of JAD 285 results in preference to treat it as a separate taxonomic unit, which will be discussed in the proceeding section as P. aff. vanuatuensis.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFA6591BFF7DFBA01391FA85.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Tanna between Ienehepe and Lighthouse, along banks of Numdretum River, 19 ° 38.558 ′ S, 169 ° 25.713 ′ E, elev. 286 m, 29 August 2018, coll. J. A. del Rosario, JAD 159 (HAY). Etymology: — rama (L.) = branch, cystidiatus (L.) = cystidia; refers to the branching apices on the pleurocystidia. Diagnosis: — Pluteus vanuatuensis f. ramacystidiatus is characterized by a glabrous and sulcate grayish brown pileus with a dark grayish brown rugose disc, and a white with fine pale brown fibrils hollow stipe with a subbulbous base. When disrupted, the tissues turn faintly grayish blue. Microcharacters include subglobose spores (7.4 × 6.4 µm), four or single-spored basidia, clavate cheilocystidia, fusoid, thick-walled pleurocystidia with variable apices being acute, hooked, or irregularly polychotomous branched, similar intermediate thinner-walled pleurocystidia with lateral hooks, an ixo-cutis pileipellis with brown plasmatic contents, and an absence of caulocystidia. Clamp connections are common in all tissues. It is differentiated from P. vanuatuensis which has a distinct floccose disc, lacks elongated branched pleurocystidia, and lacks lateral hooks on the intermediate pleurocystidia. Description: — Pileus 30 – 40 mm diam., convex to hemispherical, with a slight umbo, disc rugose-warted, margin sulcate; surface pellucid-striate up to half-way from margin, hygrophanous, semi-viscid, glabrous; disc / warts dark gray-brown (oac 639 – oac 641), surface grayish brown (oac 646 – oac 648) with patches pale pink (oac 674 – oac 676), margin slightly paler gray-brown (oac 662). Context up to 5 mm thick, pale gray-brown (oac 662). Lamellae free, moderately close with 3 – 4 tiers of lamellulae, thin (<1 mm thick), pale pink, margin somewhat paler. Stipe 25 – 35 × 3 – 4 mm, central, terete, cylindrical above a subbulbous base, hollow; surface dull, dry, fibrous, white to cream white with minute pale gray fibrils. Tissues turning bluish gray when damaged or handled. Odor indistinct. Taste indistinct. Basidiospores 6 – 8 (– 9) × 5 – 8 µm, [x m = 7.44 ± 0.78 × 6.38 ± 0.83 µm, Q = 1 – 1.6, Q m = 1.17 ± 0.2, n = 50, s = 1], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 16 – 30 × 8 – 10 µm, clavate, 4 - spored or 1 - spored, guttulate, hyaline, thin-walled, sterigmata 1.5 – 3 × 0.5 – 1 µm. Basidioles 12 – 20 × 5 – 10 µm, clavate to cylindro-clavate, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia 20 – 80 × 12 – 18 µm, clavate to cylindro-clavate, or occasionally fusoid-ventricose to narrowly utriform, obtuse or occasionally capitate-umbonate, occasionally with a guttule, hyaline, thin-walled. Pleurocystidia; primary pleurocystidia 50 – 130 × 10 – 40 µm, fusoid to narrowly lageniform, or cylindro-clavate, apex variable, obtuse without outgrowths, corniculate or occasionally cornuate with 2 – 4 (– 5) whole to bifid, acute to blunt, straight or recurved poorly or well-developed apical hooks, irregularly branched with 2 – 4 polychotomous branches, or sometimes bifid with 1 – 3 straight or recurved poorly or well-developed apical hooks per arm, majority with a guttule, hyaline, basally to apically or evenly thick-walled (up to 3 µm thick) to thin-walled; intermediate pleurocystidia 50 – 87 × 16 – 18 µm, fusoid to narrowly lageniform, apex variable, obtuse, acute, rarely mucronate, seldom irregularly branched, or cornuate with whole or rarely bifid, straight or recurved poorly or well-developed apical hooks, occasionally with 1 – 2 lateral projections, some with a guttule, hyaline, thin to evenly or centrally thick-walled. Pileipellis an ixo-cutis of repent hyphae embedded in a gelatinous matrix, composed of hyaline or with brown plasmatic pigment, non-incrusted, gelatinized or not, thin-walled, cylindrical hyphae, 5 – 24 µm diam.; terminal cells 35 – 135 × 3 – 19 µm, repent to suberect towards the disc, clavate to cylindro-clavate, obtuse, rarely with tapering apices. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 5 – 38 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 4 – 18 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 4 – 24 µm diam .. Caulocystidia absent. Clamp connections present in all tissues examined. Habitat and known distribution: — Gregarious on well-decayed wood in subtropical lowland mixed-use agro tree garden and secondary broadleaf rainforest containing Bischofia javanica (Phyllanthaceae), Burckella obovata (Sapotaceae), Claoxylon gillisonii (Euphorbiaceae), Dendrocnide latifolia (Urticaceae), Didymocheton spp. (Meliaceae), Ficus spp. (Moraceae), Garcinia pseudoguttifera (Clusiaceae), Homolanthus nutans (Euphorbiaceae), Macaranga dioica (Euphorbiaceae), and Syzygium nomoa (Myrtaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna between Ienehepe and Lighthouse, along banks of Numdretum River, 19 ° 38.558 ′ S, 169 ° 25.713 ′ E, elev. 286 m, 29 August 2018, coll. J. A. del Rosario, JAD 159 (HAY). Notes: — Pluteus vanuatuensis f. ramacystidiatus closely resembles the preceding newly described species, P. vanuatuensis, but has distinct morphological features that warrant treating it as a separate taxonomic unit. Notably, the pleurocystidia in JAD 159 display the same variation of apical ornamentation seen in all collections of P. vanuatuensis, but also contain a distinct type with elongated extensive branching elements. Phylogenetic analysis of ITS data sampling the albostipitatus / salicinus clade (Fig. 6 b) places JAD 159 sister to collections JAD 160, JAD 215, and the Vietnamese P. sp. 1 within the P. vanuatuensis clade with moderate support (BS 79 %, PP 0.99) and identical internal topology compared to the broad sampled sect. Pluteus analysis (Fig. 1 c). An identical sampling of taxa from this ITS analysis of the albostipitatus / salicinus clade using tef 1 data (Fig. 6 c) collapses the internal branches of the P. vanuatuensis clade and unites all these collections, including JAD 159. An analysis of this two-gene data (Fig. 6 a) with additional sampling of the albostipitatus / salicinus clade retrieves the internal branch topology of the P. vanuatuensis clade similar to the single gene ITS analysis (Fig. 6 b) with JAD 159 on a long branch in both the likelihood and Bayesian analyses being in a weakly supported clade with the Vietnamese P. sp. 1, JAD 160, and JAD 215 (BS 33 %, PP 0.71). Based on the two-gene analysis, the phylogenetic affinity of JAD 159 indicates it to be P. vanuatuensis. Overall, the glabrous pileus, intermediate pleurocystidia with lateral hooks, and elongated, extended branching pleurocystidia show clear morphological differences in this single collection. These distinctive features, especially the elongated branching pleurocystidia that are rare in Pluteus, justify recognition of this specimen as a distinct form of P. vanuatuensis. It may well be that P. vanuatuensis is a highly variable morphological species, and it remains to be determined if this pleurocystidia type is exclusive to glabrous forms such as JAD 159.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFA35918FF7DFA4011FEFE49.taxon	diagnosis	Diagnosis: — Pluteus aff. vanuatuensis from Tanna is characterized by a brown, glabrous pileus with a black squamulose disc and a white stipe with a subbulbous base. When disrupted, the tissues bruise bluish gray. Microcharacters include subglobose spores (7.2 × 5.8 µm), fusoid, thick-walled pleurocystidia with blunt conical protrusions at the apex, similar intermediate pleurocystidia with lesser developed apices, clavate cheilocystidia, a cutis pileipellis, an absence of caulocystidia, and clamp connections present in all tissues. Subtle differences compared to P. vanuatuensis are having a paler, glabrous, entirely pellucid-striate pileus and a more intense bruising reaction. Description: — Pileus 50 – 58 µm diam., hemispherical to plano-convex, with a slight umbo, disc pustulate / rugose; surface pellucid-striate, dry to somewhat viscid, glabrous overall, disc pustulate to minutely appressed-fibrillose towards margin; squamules / fibrils dark chocolate brown, surface pale brown overall (oac 720 – oac 722). Context up to 4 mm thick, white. Lamellae free, crowded with many tiers of lamellulae, thin, blush pink (oac 695 – oac 697). Stipe 55 – 65 × 5 – 6 mm, central, cylindrical above a subbulbous base, hollow; surface pearlescent, dry, fibrous, white overall, context white. Tissues turning blue-gray (oac 317 – oac 319) when damaged or handled. Odor indistinct. Taste indistinct. Basidiospores 6 – 8 (– 9) × (5 –) 6 – 7 µm [x m = 7.32 ± 0.68 × 5.78 ± 0.64 µm, Q = 1 – 1.3 (– 1.7), Q m = 1.28 ± 0.18, n = 50, s = 1], subglobose, seldom globose or broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 16 – 32 × 6 – 11 µm, clavate, 4 - spored, guttulate, hyaline, thin-walled, sterigmata 1.5 – 3 × 0.5 – 1 µm. Basidioles 15 – 26 × 5 – 11 µm, clavate, guttulate, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia (25 –) 32 – 52 × 10 – 18 µm, clavate, fusoid or utriform, obtuse or subcapitate-umbonate, hyaline, thin-walled. Pleurocystidia; primary pleurocystidia 55 – 100 × 13 – 24 µm, narrowly lageniform to fusoid, corniculate with 2 – 6 whole to bifid, blunt, poorly developed apical hooks, most with a guttule, hyaline, thick-walled (up to 3 µm thick); intermediate pleurocystidia (36 –) 46 – 63 × 11 – 20 µm, similar to primary but smaller and thinner-walled, narrowly lageniform to fusoid, obtuse or corniculate with 1 – 4 blunt, poorly developed apical hooks, hyaline, thin to thick-walled. Pileipellis a cutis of repent hyphae, composed of hyaline or with brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled, cylindrical hyphae, 3 – 10 µm diam.; terminal cells 52 – 138 × 9 – 18 µm, repent or becoming suberect to erect towards disc, clavate to filiform, obtuse, flexuose or tapered. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 3 – 28 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 10 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 - 12 µm diam .. Caulocystidia absent. Clamp connections present in all tissues examined. Habitat and known distribution: — Gregarious on decayed wood in subtropical lowland mixed-use agro tree garden and disturbed secondary broadleaf rainforest containing Cocos nucifera (Arecaceae), Cordia subcordata (Boraginaceae), Leucaena leucocephala (Fabaceae), Macaranga dioica (Euphorbiaceae), and Syzygium malaccense (Myrtaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna, Yakuwan, 19 ° 32.230 ′ S, 169 ° 28.911 ′ E, elev. 84 m, 15 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 285 (HAY). Notes: — Phylogenetic analysis sampling the albostipitatus / salicinus clade based on ITS (Fig. 6 b) places JAD 285 sister to all collections of the P. vanuatuensis clade with strong support. Pairwise analysis of overlapping ITS sequences shows JAD 285 to have 87.12 – 90.75 % similarity to all collections of P. vanuatuensis. The identically sampled analysis based on tef 1 data retrieves the same relationship with moderate support (BS 85 %, PP 0.97). A concatenated analysis using both genes and expanded sampling of the albostipitatus / salicinus clade (Fig. 6 a) places JAD 285 sister to a clade comprised of sequences of P. harrisii Murrill (1911: 277) and P. puttemansii Menolli Jr. & Capelari (2010: 701). It should be noted that tef 1 data is missing for many of the taxa in the expanded sampling. In the ITS analysis sampling all of sect. Pluteus, JAD 285 appears in a clade nested with P. saupei and P. vanuatuensis, however this is weakly supported (Fig. 1 c). Morphologically, JAD 285 has both primary and intermediate pleurocystidia that appear to have a higher frequency of apices with lesser developed, more rounded corniculate outgrowths, rather than the more pointed hooks typically observed in P. vanuatuensis. However, P. vanuatuensis shows extensive pleurocystidia apex variability including this type found in JAD 285, thus hardly enough of a feature that can be used to distinguish between these taxa. JAD 285 can be distinguished from P. vanuatuensis f. ramacystidiatus by the lack of a rugose disc, lack of pleurocystidia with elongated branching apices, and the presence of intermediate pleurocystidia without lateral hooks. Based on molecular data, JAD 285 appears to be a phylogenetically distinct species, despite its morphological similarities to common forms of P. vanuatuensis. As this is based on a single collection, the identity of P. aff. vanuatuensis is maintained until additional material can be collected to clearly separate this taxon from P. vanuatuensis.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFA05926FF7DFE7412D0FEFA.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Tanna, Yakuwan, 19 ° 32.230 ′ S, 169 ° 28.911 ′ E, elev. 116 m, 19 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 284 (HAY). Etymology: — Named in honor of Jean-Pascale Wahe, head of the Tafea Kaljoral Senta, for his long-time collaboration with the Plants mo Pipol blong Vanuatu project. Born and native to Tanna, this is reflected in the species’ occurrence being known only from Tanna. Diagnosis: — Pluteus wahei is characterized by a tawny brown appressed-fibrillose, dark umber disc, marginally sulcate pileus, and a silky white stipe. Some forms have a pileus that lack a distinct disc and are a paler shade of brown overall. Microcharacters include subglobose spores (5.8 × 4.5 µm), clavate cheilocystidia, fusoid-ventricose, thick-walled pleurocystidia with apical hooks, similar smaller intermediate pleurocystidia but with lateral outgrowths, a cutis pileipellis, absence of caulocystidia, and the presence of clamp connections in all tissues. Description: — Pileus 30 – 45 mm diam., convex to broadly plano-convex, slightly umbonate with a small central depression, margin slightly sulcate; surface dull turning pellucid-striate at the margin, dry, densely appressed-fibrillose or glabrous, disc punctate or rugulose; disc dark umber, fibrils tawny brown (oac 721 – oac 722), densest at disc becoming sparse towards margin, or some forms glabrous overall and pale gray-tan to almost off-white without a distinct disc. Context up to 5 mm thick, white. Lamellae free, moderately crowded with 3 tiers of lamellulae, thin, off-white to pale pink (oac 696 – oac 697). Stipe 40 – 70 × 3 – 4 mm, central, terete, cylindrical, solid; surface pearlescent, dry, silky, white overall, context white. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 (– 8) × 4 – 5 (– 6) µm [x mr = 5.62 – 5.94 × 4.1 – 4.84 µm, x mm = 5.78 ± 0.22 × 4.47 ± 0.09 µm, Q = 1 – 1.6 (– 2), Q mr = 1.24 – 1.38, Q mm = 1.31 ± 0.09, n = 50, s = 2], subglobose to broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 18 – 29 × 4 – 8 µm, clavate, 4 - spored, hyaline, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 11 – 24 × 4 – 8 µm, clavate, hyaline, thin-walled. Cheilocystidia 28 – 58 × 8 – 22 µm, clavate to cylindro-clavate, seldom fusoid-ventricose, obtuse or rarely umbonate, hyaline, thin-walled. Pleurocystidia; primary pleurocystidia (56 –) 65 – 80 (– 96) × 14 – 20 µm, lageniform to fusoid-ventricose, cornuate with 2 – 4 whole, straight to recurved seldom poorly or well-developed apical hooks, rarely with 1 – 2 lateral excrescences, hyaline, thick-walled; intermediate pleurocystidia 31 – 56 (– 70) × 10 – 16 µm, similar to primary but smaller and thinner-walled, lageniform to fusoid-ventricose, frequently corniculate with 1 – 3 blunt, poorly developed apical hooks or occasionally cornuate with 1 – 3 straight to recurved well-developed hooks, occasionally with 1 – 3 lateral excrescences, hyaline, thin to thick-walled. Pileipellis a cutis of repent hyphae, composed of hyaline or with pale brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled, cylindrical hyphae, 8 – 22 µm diam.; terminal cells 50 – 112 × 7 – 16 µm, repent to suberect towards disc, clavate to filiform, obtuse to capitate, some entirely nodulose. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindro-clavate hyphae, 5 – 30 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 4 – 12 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 5 – 18 µm diam .. Caulocystidia absent. Clamp connections present in all tissues examined. Habitat and known distribution: — Gregarious on decaying wood in subtropical lowland mixed-use agro tree garden and disturbed secondary broadleaf rainforest containing Cocos nucifera (Arecaceae), Cordia subcordata (Boraginaceae), Leucaena leucocephala (Fabaceae), Macaranga dioica (Euphorbiaceae), and Syzygium malaccense (Myrtaceae) and primary broadleaf rainforest containing Dysoxylum aneityense (Meliaceae), Ficus adenosperma (Moraceae), Hedycarya dorstenioides (Monimiaceae), Inocarpus fagifer (Fabaceae), Kermadecia lutea (Proteaceae), Macaranga dioica (Euphorbiaceae), Myristica fatua (Myristicaceae), and Syzygium myriadenum (Myrtaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna, at Transect 7, Kwaprapra, Iatukwei, 19 ° 34.255 ′ S, 169 ° 27.093 ′ E, elev. 252 m, 11 December 2017, coll. J. A. del Rosario, JAD 107 (HAY); Tanna, Yakuwan, 19 ° 32.230 ′ S, 169 ° 28.911 ′ E, elev. 116 m, 19 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 284 (HAY). Notes: — Historically there has been difficulty in identification and taxonomy of certain species in sect. Pluteus, especially when some pigmented species like P. cervinus (Schaeffer) Kummer (1871: 99) or P. pouzarianus Singer (1983: 283) are known to produce pure white or paler-colored morphotype variants (Justo et al., 2014). The use of microcharacteristics in combination with molecular data has been crucial for the taxonomy of this group. Pluteus wahei produces basidiomes with pale forms that may resemble a number of species. The Sri Lankan P. aglaeotheles (Berkeley & Broome) Saccardo (1887: 676) produces a pale basidiome and shares similarly sized and shaped spores and pleurocystidia with P. wahei, but differs significantly due to the lamellar edge containing metuloid cystidial elements, the pileipellis lacking nodulose elements, and clamp connections being absent (Pegler 1986, Singer 1956). Pluteus brunneidiscus Murrill (1917: 131) was noted to have lateral outgrowths on the terminal cells of the pileipellis, but compared to P. wahei has larger spores, seldom has lateral outgrowths on the cystidia, and has a superficially different squamulose pileus (Banerjee & Sundberg 1993, Justo et al. 2014, Singer 1956). The dark pigmented pileus form of P. wahei is comparable to tropical species such as P. subcervinus (Berkeley & Broome) Saccardo (1887: 666) and P. fibulatus Singer in Singer & Digilio (1952: 252). Pluteus subcervinus was originally described from Sri Lanka (Berkeley & Broome 1871) and since then has been reported from Tanzania (Pegler 1977), Indonesia (according to Pegler 1986), India (Pradeep et al. 2002), and recently Vietnam (Malysheva et al. 2020). Pluteus subcervinus differs from P. wahei in having a non-nodulose pileipellis, highly branched pleurocystidia, and in producing a paler camel brown pileus. Pluteus fibulatus tends to produce a darker brown pileus and stipe, has more apically variable pleurocystidia and non-nodulose pileipellis cells (Campi et al. 2019, Singer 1958, Singer & Digilio 1952). Phylogenetic analysis of ITS data (Fig. 1 b) places P. wahei on a supported branch, sister to the petasatus clade (BS 100 %, PP 1.0) with a recently described taxon P. olivaceofibrillosus E. F. Malysheva & A. V. Alexandrova (2020: 84). Pluteus wahei separates itself from species of Justo et al. ’ s (2014) petasatus clade by the presence of clamp connections on the pileipellis compared to a lack of clamp connections in P. petasatus and P. leucoborealis Justo, E. F. Malysheva, Bulyonkova & Minnis (2014: 58), a non-pigmented stipe, pleurocystidia with lateral hooks, nodulose pileipellis cells, and lack of a squamulose disc compared to P. pellitus (Persoon) Kummer (1871: 98). The pileus color of the pale morphotype of P. wahei strongly resembles the Vietnamese P. olivaceofibrillosus, but differs from this taxon in lacking a distinct disc. Both color variants of P. wahei share a sulcate margin and have a striate fibrillose pileus similar to P. olivaceofibrillosus, but the pigmented morphotype mainly differs in having a darker, tawny brown pileus. Micromorphologically, both species share multiple characters, but ultimately P. wahei is separated by the intermediate pleurocystidia having lateral hooks and a mix of poorly to well-developed apical hooks rather than being only mucronate, and the pileipellis terminal elements being nodulose and capitate (Malysheva et al. 2020). Pluteus wahei is recognized as a distinct species from P. olivaceofibrillosus and described as new due to the morphological differences in combination with phylogenetic data.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF9A592CFF7DFF3911F3F83D.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Aneityum, Nopsjec. 19 ° 12.444 ′ S, 169 ° 25.916 ′ E, elev. 222 m, 11 December 2019, coll. J. A. del Rosario, JAD 344 (HAY). Etymology: — aureo (L.) = golden, fuscus (L.) = grayish brown; refers to the golden and gray-brown color of the pileus and stipe. Diagnosis: — Pluteus aureofuscus from Tafea Province is characterized by a golden cream and pinkish brown to pale tan finely fibrillose-flocculose colored pileus with a sulcate margin, and a similarly colored and ornamented stipe with a bulbous base. Microcharacters include globose spores (7.0 × 6.3 µm), clavate cheilocystidia, fusoid-ventricose pleurocystidia with some having median or apical septa and small forms with an apical mucronate appendage, a pileipellis arranged as a euhymeniderm to trichoderm composed of broadly clavate to fusoid-ventricose cells mixed with subglobose to pyriform terminal elements overlaying a cutis subpelllis, and clavate caulocystidia. Description: — Pileus 14 – 46 mm diam., hemispherical expanding to convex without or with a slight umbo, margin sulcate; surface dull becoming pellucid-striate in age, hygrophanous, finely appressed-fibrillose to finely flocculose, disc minutely pustulate becoming subtomentose in age; fibrils, floccules, and pustules pallid tan (oac 709 – oac 711) with dull pinkish brown (oac 667 – oac 669) tones becoming off-white in age, surface golden cream-colored, becoming gray to off-white in age. Context up to 1.5 mm, white. Lamellae free, crowded with 4 tiers of lamellulae, thin, cream white initially, turning pale pink (oac 633 – oac 634) in age. Stipe 14 – 45 × 3 – 4 mm, central, solid, terete, cylindrical over a subbulbous to bulbous base; surface dull, dry, pallid tan (oac 709 – oac 711) appressed-fibrillose to minutely flocculose over a cream-colored to off-white surface or glabrous in age, context white. Odor indistinct. Taste indistinct. Basidiospores 6 – 8 (– 9) × 6 – 8 µm [x mr = 6.78 – 7.24 × 6.02 – 6.68 µm, x mm = 7.03 ± 0.23 × 6.32 ± 0.33 µm, Q = 1 – 1.6, Q mr = 1.09 – 1.13, Q mm = 1.12 ± 0.08, n = 50, s = 3], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 18 – 36 × 7 – 11 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 1.5 – 3 × 0.5 – 2 µm. Basidioles 18 – 30 × 6 – 9 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia (24 –) 31 – 65 (– 90) × (11 –) 16 – 36 µm, narrowly to broadly clavate, fusoid or sphaeropedunculate, obtuse, hyaline, thin-walled. Pleurocystidia 60 – 92 (– 120) × 18 – 36 (– 40), uncommon to common, fusoid-ventricose to narrowly lageniform, obtuse, or (20 –) 35 – 91 × 7 – 18 (– 20) µm, lageniform to fusoid-ventricose, commonly to rarely mucronate (3 – 12 µm long), occasionally medially or apically septate in some collections or not, hyaline, thin-walled. Pileipellis a fragmented to complete ascending euhymeniderm to trichohymeniderm overlying a cutis subpellis, terminal elements typically 60 – 160 × 14 – 32 (– 43) µm, scattered or in ascending fascicles, narrowly to broadly clavate, fusoid-ventricose or rarely filiform, obtuse, rarely acute, or capitate or sometimes 42 – 70 × 21 – 40 µm, sphaeropedunculate to pyriform, obtuse or occasionally capitate-mucronate, hyaline or with pale brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled; subpellis a cutis of repent hyphae, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 16 µm diam .. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 2 – 25 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 12 µm diam .. Stipitipellis a cutis, composed of hyaline or with pale grayish brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 10 µm diam .. Caulocystidia 24 – 68 (– 82) × 7 – 15 (– 18) µm, scarce to abundant in fascicles, cylindro-clavate to broadly clavate, seldom fusoid, obtuse or capitate, with pale grayish brown plasmatic pigment or hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary to gregarious on decaying wood in subtropical montane primary broadleaf- Araucariaceae / Podocarpaceae rainforest containing Agathis macrophylla (Araucariaceae), Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Dendrocnide latifolia (Urticaceae), Ficus septica (Moraceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Geissois denhamii (Cunoniaceae), Hernandia moerenhoutiana (Hernandiaceae), Macaranga dioica (Euphorbiaceae), Podocarpus vanuatuensis (Podocarpaceae), Polyscias cissondendron (Araliaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Tanna, Aneityum). Material examined: — VANUATU. Tafea Province: Tanna, Lighthouse area. 19 ° 38.387 ′ S, 169 ° 25.923 ′ E, elev. 155 m, 6 December 2018, coll. J. A. del Rosario, JAD 218 (HAY); Aneityum, Noposjec. 20 ° 12.649 ′ S, 169 ° 46.974 ′ E, elev. 184 m, 11 December 2019, coll. J. A. del Rosario, JAD 342 (HAY); Aneityum, Nopsjec. 19 ° 12.444 ′ S, 169 ° 25.916 ′ E, elev. 222 m, 11 December 2019, coll. J. A. del Rosario, JAD 344 (HAY). Notes: — The specimens of P. aureofuscus exhibit minor morphological variation. Collection JAD 344 consists of younger basidiomes with an overall golden cream-colored pileus surface and stipe streaked with pallid tan fibrils and floccules. JAD 342 contains more mature basidiomes with the same golden cream-colored pileus and stipe, however the fibrils and floccules turn gray with dull pinkish brown streaks. JAD 218 is well-aged, with the pileus turning entirely gray similar to JAD 342, however the dull pinkish brown tones remain. Microscopically, all three collections are similar with a few notable differences. JAD 218 and JAD 342 share a high frequency of apically mucronate pleurocystidia, while this cystidia type was only observed once in JAD 344. In particular, JAD 342 contains pleurocystidia with distinct singular septa, either towards the apex or at the median. Septate cystidia are rare in Pluteus spp., with P. septocystidiatus being a well-documented species that produces a fuscous pileus, contains thick-walled pleurocystidia, a cutis pileipellis, with the septate cell type occurring in both pleurocystidia and cheilocystidia (Ševčíková et al. 2014). Overall, the shared micromorphology between the collections of P. aureofuscus would be clavate or sphaeropedunculate cheilocystidia, a pileipellis consisting of clavate, fusoid-ventricose and subglobose elements, and clavate subcapitate caulocystidia. The variable appearance of P. aureofuscus suggests comparison to species that physically encompass a similar range or are closer to one of the forms. Pluteus sulcatus Singer in Singer & Digilio (1952: 265) from Argentina is very close, but differs in having a more fuscous pileus, smaller cheilocystidia (21 – 23 × 12 µm), and lacks pyriform elements in the pileipellis (Singer 1956, 1958, Singer & Digilio 1952). Another similar Argentinean species, P. hiemalis Singer (1958: 248), differs microscopically in lacking mucronate pleurocystidia and pyriform pileipellis elements (Singer 1958). The Sri Lankan P. glyphidiatus (Berkeley & Broome) Saccardo (1887: 673) has a very similar stature, is yellow and translucent to grey and squamulose (Pegler 1986), but differs microscopically with smaller non-mucronate pleurocystidia, both pleurocystidia and cheilocystidia having incrustations, and the absence of pyriform pileipellis elements (Pegler 1986, Singer 1956). Pluteus pelinus (Berkeley & Broome) Saccardo (1887: 675) is another similar Sri Lankan species, but differs microscopically by having non-mucronate pleurocystidia, smaller pleurocystidia and cheilocystidia, and an overall repent cutis pileipellis (Pegler 1986). Phylogenetic analysis based on ITS data (Fig. 14 b) places the Vanuatu collections in a moderately supported clade (BS 89 %, PP 0.99) with weakly supported internal topology containing several unidentified species: P. decoloratus Horak (2008: 24), P. subroseus E. F. Malysheva (2023: 23), Vanuatu collection JAD 302, and P. albidus Beeli (1928: 82). Pluteus decoloratus described from New Zealand is similar macromorphologically to P. aureofuscus, but differs micromorphologically in having non-mucronate pleurocystidia, longer trichodermal pileipellis elements (100 – 270 × 24 – 30 µm) and lacking caulocystidia (Horak 2008). Pluteus albidus is very similar micromorphologically, especially in the clavate-mucronate pleurocystidia, but both the cheilocystidia (32 – 48 × 11 – 20 µm) and pleurocystidia (37 – 54 × 11 – 20 µm) are much smaller, lack septa, and the basidiome is white overall without contrasting colored fibrils / floccules (Desjardin & Perry 2018). Pluteus subroseus also shares similar micromorphology, but has smaller cheilocystidia (33 – 45 × 12 – 25 µm) and pleurocystidia (56 – 85 × 14 – 30 µm), thick-walled pileipellis elements, and an overall paler basidiome with a beige-red pileus disc (Malysheva et al. 2023).	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF9A592CFF7DFF3911F3F83D.taxon	description	= Pluteus conizatus var. africanus E. Horak, Bulletin du Jardin Botanique National de Belgique 47 (1 – 2): 89 (1977) Diagnosis: — As represented by material from Tafea Province, P. chrysaegis is characterized by a sulfur yellow glabrous pileus with a light brown veined rugose-venose disc, and a tan brown longitudinally fibrillose stipe with a bulbous base. A second morphotype from Tanna Island exists with a pale brown pileus (Fig. 16 b). Microcharacters include globose spores (6 × 5.4 µm), lageniform, acute, thin to thick-walled cheilocystidia, broadly lageniform, thick-walled pleurocystidia, a hymeniderm pileipellis composed of pyriform cells intermixed with fusoid pileocystidia arising from a cutis subpellis, and clavate to fusoid caulocystidia. Description: — Pileus 30 – 60 mm diam., hemispherical expanding to plano-convex, with a slightly depressed broad umbo; surface pellucid-striate up to half-way from margin, dry to viscid, glabrous, disc rugose-venose radiating towards the margin; tan-brown (oac 686 – oac 687) in age, or if not, disc veins and wrinkles light to dark brown (oac 690 – oac 691 / oac 721 – oac 722), fading towards margin, surface sulfur to pale yellow (oac 896 – oac 897) turning pale (oac 898 – 899) towards disc with translucent patches exposing underlying white context tissue. Context up to 3 mm thick, white. Lamellae free, crowded with 4 tiers of lamellulae, thin, pink-brown (oac 619 – oac 620). Stipe 28 – 65 × 4 – 6 mm, central, terete, cylindrical with a subbulbous base, solid; surface dull, dry, tannish brown (oac 643 – oac 645) longitudinally fibrillose over an off-white base, context white. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 (– 8) × 4 – 6 (– 7) µm [x mr = 5.55 – 6.7 × 4.94 – 5.38 µm, x mm = 6.11 ± 0.59 × 5.19 ± 0.22 µm, Q = 1 – 1.6, Q mr = 1.12 – 1.28, Q mm = 1.18 ± 0.09, n = 50, s = 3], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 18 – 28 × 5 – 8 µm, clavate, 4 - spored, guttulate, hyaline, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 15 – 28 × 5 – 8 µm, clavate, guttulate, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia 28 – 62 × 5 – 18 µm, lageniform or fusoid, acute or capitate, hyaline, thin to thick-walled (up to 2 µm thick) especially at the apex. Pleurocystidia typically 50 – 110 × 13 – 34 µm, broadly clavate to narrowly lageniform, obtuse or truncate, hyaline, thin to thick-walled (up to 2 µm thick); rarely 35 – 56 × 8 – 18 µm, fusoid to lageniform, obtuse with 2 – 4 poorly developed apical outgrowths or capitate, hyaline, thin-walled. Pileipellis an epithelioid hymeniderm with pileocystidia over a subpellis, composed of a majority of cells 8 – 30 × 8 – 15 µm, subglobose to pyriform or sphaeropedunculate, obtuse, some capitate or mucronate, hyaline or sometimes with pale amber brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled; pileocystidia 26 – 75 × 8 – 22 µm, fusoid to lageniform, acute, capitate or mucronate, hyaline or sometimes with pale amber brown plasmatic pigment, thin-walled; subpellis a cutis of repent hyphae, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 10 µm diam .. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical to inflated hyphae, 3 – 18 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 20 µm diam .. Stipitipellis a cutis, composed of hyaline or often with pale brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 10 µm diam .. Caulocystidia 14 – 45 × 8 – 15 µm, scattered to clustered, clavate or fusoid to lageniform, acute or mucronate, hyaline or sometimes with pale brown plasmatic pigment, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary on decaying wood in subtropical montane primary broadleaf rainforest to cloud forest containing Balanops pedicellata (Balanopaceae), Diospyros sp. (Ebenaceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Ilex vitiensis (Aquifoliaceae), Melicope latifolia (Rutaceae), Metrosideros collina (Myrtaceae), Plerandra actinostigma (Araliaceae), Scaevola cylindrica (Goodeniaceae), Semecarpus tannaensis (Anacardiaceae), and Syzygium spp. (Myrtaceae); montane transitionary secondary to primary broadleaf- Podocarpaceae rainforest containing Burckella obovata (Sapotaceae), Cryptocarya tannaensis (Lauraceae), Dacrycarpus imbricatus (Podocarpaceae), Elaeocarpus floridanus (Elaeocarpaceae), Ficus smithii (Moraceae), Hernandia moerenhoutiana (Hernandiaceae), Melicope sp. (Rutaceae), Metrosideros vitiensis (Myrtaceae), Meryta neoebudica (Araliaceae), and Neuburgia corynocarpa (Loganiaceae); and montane primary broadleaf cloud forest containing Atractocarpus sezitat (Rubiaceae), Claoxylon psilogyne (Euphorbiaceae), Eumachia trichostoma (Rubiaceae), Geissois denhamii (Cunoniaceae), Ficus septica (Moraceae), Neonauclea forsteri (Rubiaceae), and Schefflera neoebudica (Araliaceae), Vanuatu (Tanna, Aneityum, Futuna). Also known from Africa (D. R. Congo, São Tomé) and Asia (China, India, Sri Lanka, Vietnam). Material examined: — VANUATU. Tafea Province: Tanna, coastal forest near Kwamera, 19 ° 38.467 ′ S, 169 ° 26.078 ′ E, elev. 110 m, 6 December 2018, coll. J. A. del Rosario, JAD 217 (HAY); Aneityum, Mount Inhetiji, lowland forest in former taro terraces, 20 ° 12.552 ′ S, 169 ° 51.107 ′ E, elev. 140 m, 12 December 2018, coll. J. A. del Rosario & B. Nasawman, JAD 248 (HAY); Futuna, Mount Tatafu, upper slopes, 19 ° 31.759 ′ S, 170 ° 12.683 ′ E, elev. 645 m, 22 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 312 (HAY). Notes: — Pluteus chrysaegis (Berkeley & Broome) Petch (1912: 271) was described and known only from Sri Lanka (Berkeley & Broome, 1871) until material was collected and re-described from India (Pradeep et al. 2012, Pradeep & Vrinda 2006). Additional recent reports have expanded its known distribution to include equatorial coastal Central Africa (Desjardin & Perry 2018), southern China (Hosen et al. 2018), and Vietnam (Malysheva et al. 2023). Molecular data retrieved from GenBank (MF 153092 and MH 212067) of additional material included in ITS phylogenetic analysis suggest the presence of the species in Florida, U. S. A .. The material collected throughout Tafea Province matches well with descriptions from previous regional accounts with minor exceptions being that the basidiospores and pleurocystidia are both slightly larger than previously reported size ranges. One feature observed in the Tafean collections is an additional form of pleurocystidia that differs by being smaller, thin-walled, and with capitate or mucronate apical projections. This pleurocystidia type has not been not observed in other reports until recently reported in a study by Malysheva et al. (2023).	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF9A592CFF7DFF3911F3F83D.taxon	description	The presence of another morphotype of an entirely brown rather than yellow pileus, additional form of pleurocystidia, and varying thickness of the cheilocystidia indicates a broader known morphological variation in P. chrysaegis. The differing observations of pigmentation in the pileipellis and stipitipellis is another example of this variability, but combined with molecular data this also presents a strong case that P. conizatus var. africanus is likely conspecific with P. chrysaegis.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF935929FF7DFF541204F8A0.taxon	diagnosis	Diagnosis: — Pluteus cf. fastigiatus from Tanna is characterized by a campanulate, marginally sulcate dark brown fibrillose-rimose pileus with a dark brown squamulose disc, and a white stipe finely covered with gray fibrils. Microcharacters include subglobose spores (6.2 × 5.0 µm), broadly clavate, acute cheilocystidia, lageniform pleurocystidia, a euhymeniderm pileipellis of broadly clavate cells mixed with fusiform, sometimes thick-walled cells containing brown plasmatic pigment, fusoid-ventricose caulocystidia, and an absence of clamp connections. Description: — Pileus 45 mm diam., campanulate to convex with a slight umbo, slightly sulcate up to a quarter from margin; surface dull, dry, densely appressed-fibrillose and radially slightly splitting to expose the underlying white context, disc squamulose; squamules and fibrils dark brown (oac 638 – oac 640), darkest and densest at the disc, fading towards margin, underlying surface white to off-white. Context up to 2 mm thick, white. Lamellae free, close with 3 – 4 tiers of lamellulae, thin, undulate, white to off-white. Stipe 45 × 5 mm, central, terete, cylindrical over a subbulbous base, solid; surface pearlescent, dry, fibrous, fine gray fibrils over a white to off-white surface, context white. Odor indistinct. Taste indistinct. Basidiospores (5 –) 6 – 7 × (4 –) 5 – 6 µm [x m = 6.2 ± 0.49 × 4.96 ± 0.53 µm, Q = 1 – 1.5, Q m = 1.26 ± 0.14, n = 50, s = 1], subglobose to broadly ellipsoid, smooth, with a guttule, inamyloid, thick-walled. Basidia 20 – 30 × 6 – 10 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 16 – 25 × 5 – 10 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 40 – 68 × 13 – 26 µm, broadly clavate to fusoid-ventricose, obtuse, occasionally acute or subcapitate, hyaline, thin-walled. Pleurocystidia 35 – 78 × 15 – 28 µm, scattered, fusiform to lageniform, obtuse, rarely centrally strangulate, hyaline, thin-walled. Pileipellis a euhymeniderm with pileocystidia, composed of a majority of cells 50 – 90 × 8 – 28 µm, erect to suberect, clavate to broadly clavate or cylindro-clavate, obtuse or rarely subcapitate, erect to suberect, hyaline or with pale brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled; pileocystidia 60 – 112 × 10 – 18 µm, abundant, erect to suberect, fusiform to lageniform, obtuse or seldom capitate, hyaline or with brown to pale brown plasmatic pigment, thin to sometimes thick-walled. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled hyphae, 8 – 30 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 4 – 16 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 5 – 13 µm diam .. Caulocystidia 40 – 80 × 8 – 24 µm, solitary to clustered, fusiform to fusoid-ventricose or clavate, obtuse or occasionally subcapitate to capitate, hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary on decayed wood in subtropical lowland mixed-use agro tree garden and secondary broadleaf rainforest containing Bischofia javanica (Phyllanthaceae), Burckella obovata (Sapotaceae), Claoxylon gillisonii (Euphorbiaceae), Dendrocnide latifolia (Urticaceae), Didymocheton spp. (Meliaceae), Ficus spp. (Moraceae), Garcinia pseudoguttifera (Clusiaceae), Homolanthus nutans (Euphorbiaceae), Macaranga dioica (Euphorbiaceae), and Syzygium nomoa (Myrtaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna, along banks of Numdretum River, 19 ° 38.661 ′ S, 169 ° 25.708 ′ E, elev. 115 m, 30 August 2018, coll. J. A. del Rosario, JAD 170 (HAY). Notes: — Pluteus fastigiatus Singer in Singer & Digilio (1952: 259) is a species currently known only from Argentina (Singer & Digilio 1952), and although the Vanuatu specimen matches well with many of its characters, the ambiguity of the original description and similarity to other species prevents a conclusive identification. Macromorphologically, the Vanuatu material shares the dark brownish gray fibrillose-rimose pileus with an appressed-squamulose disc. Micromorphologically, the pleurocystidia match in shape, size, and absence of incrustation, the cheilocystidia are similarly shaped and only slightly shorter (21.5 – 80 × 11.3 – 30 µm), and the spores are similar in size, but lack “ macrospores ” (9 – 11 × 7 – 8.5 µm) that Singer stated only occurred in carpophores with 1 – 3 - spored basidia (Singer 1956, 1958, Singer & Digilio 1952). The main differing and ambiguous character is the pileipellis, which based on a compilation of descriptions appears to be a cutis with ascending terminal cells transitioning to a palisade at the disc. This may somewhat resemble the arrangement in the Vanuatu material, which this study prefers to treat as a euhymeniderm as the terminal elements are all erect, or at the least suberect, resembling a palisade throughout the pileipellis. Overall, these terminal elements arise from the interwoven pileus trama with one to two basal septate cells, and are not so much in chains with multiple elongate basal septate cells such as in a typical trichoderm. Pluteus fastigiatus also apparently has no obvious cutis that this study treats as a subpellis or what Singer typically describes as a “ hypodermium ” (Singer 1958). From all the descriptions, Singer only provides one illustration of a pileipellis cell (Fig. 12 e, Singer 1956), which is similar to one aspect of the pileipellis elements from the Vanuatu material. Singer emphasized two cell types: broader cells having smaller basal elements and narrow cells being the terminal elements of a longer chain, both being apically rounded. Compared to the Vanuatu material, this may parallel the clavatefusoid and narrowly lageniform elements, respectively. Even the size of these terminal elements in P. fastigiatus are ambiguous, although Singer does not provide measurements in the original circumscription, a misprint from different re-descriptions appears as “ 53 – 80 × 16 – 0 µm ” (Singer 1956) and “ 43 – 117 × 8 – 4.3 µm ” (Singer 1958). Nevertheless, the pileipellis cell length for both overlaps, and it could be assumed that the width of these elements reach at most up to 16 µm, which are both within the Vanuatu material’s size range. A re-examination of the type and additional material to clearly categorize the pileipellis with other characters and sampling for molecular analysis may aid in confirming the identity of this material. For now, it is preferred to tentatively identify the Vanuatu specimen as P. cf. fastigiatus. Singer considered the predominantly attenuate cheilocystidia, which also occur in the Vanuatu material, in P. fastigiatus to separate it from P. spilopus (Berkeley & Broome) Saccardo (1887: 669). Pluteus spilopus shares a similar stature to the Vanuatu specimen, but the stipe has distinct black dots that Singer compares to Gomphidius maculatus (Scopoli) Fries (1838: 319), which may be interpreted as being squamose (Singer 1956). Pluteus spilopus also differs microscopically due to slightly shorter obtuse cheilocystidia, broadly clavate pleurocystidia, and a repent cutis pileipellis (Pegler 1986, Singer 1956). The Vanuatu material’s tapered lageniform pileipellis elements may be interpreted as subacute, suggesting comparison to similar taxa with this trait that Singer considered important in establishing his morphological stirps. The Bolivian P. pluvialis Singer (1958: 234) was initially considered for the identity of the Vanuatu material due to similar basidiome stature and similar pileipellis elements. According to the original description, this species also has an ambiguous pileipellis that appears to be a cutis with ascending terminal elements in bunches, but Singer later categorized the species in stirps Fuliginosus which is characterized by a trichodermium type pileipellis with subacute or acuminate terminal cells (Singer 1958, 1986). Nevertheless, P. pluvialis ultimately differs in the presence of a tomentose pileus, abruptly bulbous stipe, incrusted lamellar cystidia, less lageniform pleurocystidia, and significantly larger pileipellis elements (82 – 165 × 16.5 – 19.5 µm) (Singer 1958). Menolli and Capelari (2016) determined a specimen from Brazil as P. cf. fastigiatus, and this differs from the Vanuatu material by the slightly smaller spores, more clavate incrusted pleurocystidia, lack of caulocystidia, and a cutis pileipellis without obtuse elements.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF915935FF7DF86C1479FDB1.taxon	diagnosis	Diagnosis: — Pluteus fernandezianus from Aneityum is characterized by a pileus with a disc composed of radiating dark brown pustules fading towards the margin over a pallid tan surface, marginate lamellae with a grayish brown edge, and a white stipe with minute grayish brown fibrils concentrating at the bulbous base. Microcharacters include broadly ellipsoid basidiospores (7.8 × 6.1 µm), clavate pale brown pigmented cheilocystidia, lageniform infrequently pale brown pigmented pleurocystidia, a trichodermal pileipellis made up of filiform pale brown pigmented terminal elements, narrowly clavate capitate pale brown pigmented caulocystidia, and an absence of clamp connections. Description: — Pileus 45 – 50 mm diam., hemispherical to plano-convex with a minute flattened umbo, disc somewhat rugulose; surface dull, dry, velutinous to pruinose at the disc, radiating outwards and appearing as dense pustules under a hand-lens, glabrous elsewhere; pustules dark brown (oac 734 – oac 736), surface pallid tan (oac 688 – oac 689). Context up to 3 mm thick, white. Lamellae free, close, with 3 – 4 tiers of lamellulae, some bifurcate, thin, pale pink (oac 758 – oac 760), margin pallid tan (oac 688 – oac 689). Stipe 45 – 48 × 4 – 5 mm, central, terete, hollow; surface dull, dry, finely fibrillose especially at the base, grayish brown fibrils over a white to off-white surface, context white. Odor indistinct. Taste indistinct. Basidiospores 7 – 8 (– 9) × 5 – 7 µm [x m = 7.8 ± 0.45 × 6.1 ± 0.52 µm, Q = 1.14 – 1.4, Q m = 1.28 ± 0.09, n = 50, s = 1], subglobose to broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 20 – 36 × 5 – 8 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 15 – 22 × 6 – 8 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 28 – 60 (– 80) × 12 – 23 µm, narrowly to broadly clavate or rarely fusoid-ventricose, obtuse, with pale brown plasmatic pigment or sometimes hyaline, thin-walled. Pleurocystidia 70 – 98 (– 103) × 15 – 30 µm, broadly to narrowly lageniform or sometimes fusoid, obtuse or sometimes nodulose-capitate, hyaline or occasionally with pale brown plasmatic pigment, thin-walled. Pileipellis a trichoderm to trichohymeniderm with erect fascicles, especially towards the disc, terminal elements 64 – 105 × 8 – 25 µm, clavate to cylindro-clavate or narrowly filiform, obtuse or rarely subcapitate, with pale brown plasmatic pigment or hyaline, non-incrusted, non-gelatinous, thin-walled. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 3 – 20 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 14 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 10 µm diam .. Caulocystidia 40 – 75 × 6 – 12 µm, uncommon, solitary to clustered, narrowly clavate to filiform, obtuse or frequently mucronate-capitate, typically with brown plasmatic pigment or hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on wood in subtropical montane transitionary primary to secondary broadleaf- Podocarpaceae rainforest containing Burckella obovata (Sapotaceae), Cryptocarya tannaensis (Lauraceae), Dacrycarpus imbricatus (Podocarpaceae), Elaeocarpus floridanus (Elaeocarpaceae), Ficus smithii (Moraceae), Hernandia moerenhoutiana (Hernandiaceae), Melicope sp. (Rutaceae), Metrosideros vitiensis (Myrtaceae), Meryta neoebudica (Araliaceae), and Neuburgia corynocarpa (Loganiaceae), Vanuatu (Aneityum). Also known from Chile (Juan Fernandez Islands) and Argentina. Material examined: — VANUATU. Tafea Province: Aneityum, Nethwanethervana, 20 ° 12.027 ′ S, 169 ° 47.727 ′ E, elev. 317 m, 10 December 2019, coll. J. A. del Rosario, JAD 331 (HAY). Notes: — Pluteus fernandezianus Singer (1958: 220) was originally described by Singer (1958) from the Juan Fernandez Islands located off the western coast of Chile and was placed in stirps Plautus and then in stirps Umbrosus (Singer 1986). According to Niveiro and Albertó (2012) the species has also been reported in Argentina by Raithelhuber (1991). A study by Menolli and Capelari (2013) of Brazilian Pluteus spp. collections by P. C. Hennings and J. Rick, concluded P. velatus Rick (1961: 417) should be considered a nomen dubium based on their observations that the type material is inconsistent with the type description. According to Menolli and Capelari, the pileus and lamellae edge color from the type description combined with their examination led them to suggest the possible identity of P. fernandezianus, however its presence in Brazil remains unconfirmed. The Vanuatu specimen would fit well compared to the original protologue description of P. fernandezianus, but with a few caveats. The Vanuatu material displays very similar pileus features, but are larger than what was originally described by Singer. Singer (1958) noted the pileus being 14 mm broad when dried, which may lead to the assumption many of these observations were on dried material that may have been larger when fresh. Singer described the stipe as being pallid white and maybe darkening towards the base, but noted it as not being any sort of fuscous or fuliginous fibrillose, but rather somewhat pubescent-subpruinose. The Vanuatu specimen, also at first glance has an overall white stipe, however with the aid of a hand-lens it is possible to see that there are very fine grayish brown fibrils which are easily overlooked. Singer’s observations based on dried material may suggest this character is less distinctive in old material. Regarding microscopic characters, the Vanuatu specimen matches in the size and shape of the spores, and the shape and pigmentation of the pleurocystidia, cheilocystidia, and pileipellis terminal cells. The Vanuatu material’s pleurocystidia shape and apex ornamentation especially match the pleurocystidia of Singer’s Chilean material described as “ … the tip sometimes short apiculate in the center, sometimes sinuate or nodulose at the apex, ” (Singer 1958). The main difference is that Singer’s specimens have slightly shorter cheilocystidia (33 – 48 × 8.7 – 19 µm) and pleurocystidia (46 – 65 × 8.7 – 23.3 µm) compared to this material. Singer also did not include caulocystidia in the original description, which may indicate re-examination of the holotype is necessary. Menolli et al. (2015 c) also acknowledged that Singer (1969) considered P. brunneoolivaceus Horak (1964: 165) a synonym of P. fernandezianus, but without elaboration. Based on a comprehensive comparison of the type descriptions of these species, Singer may have related the two due to the similarities of the basidiomes and the marginate lamellae. Horak described the pleurocystidia of P. brunneoolivaceus as having an apex “ subcapitata, cornuis nullis, saepissmime verruciformibus vel digitiformibus … ” (Horak 1964) compared to Singer’s P. fernandezianus pleurocystidia being “ … sometimes short apiculate in the center, sometimes sinuate or nodulose ” (Singer 1958). Based on Horak’s accompanying plate illustrations (Tab. 1, 1 a – g; Horak 1964) and a re-description of the holotype (Horak 1980 b) the pleurocystidia on P. brunneoolivaceus appear to be digitate or cornuate and have apically thickened walls similar to metuloids in sect. Pluteus, which in the protologue (Horak 1964) are comparable to the metuloids in P. cervinus. Confusingly, in the re-description of P. brunneoolivaceus the thick-walled pleurocystidia are not mentioned but illustrated (Lamina XXV, v; Horak 1980 b). Re-examinations of these type specimens in addition to analysis with molecular data are necessary to clarify the relationships between these taxa. Nevertheless, based on the type descriptions, none of these species conform with the material from Vanuatu. Menolli et al. (2015 c) tentatively identified specimen “ RSPF 330 ” deposited in the RSPF Herbarium at the Universidade de Passo Fundo in Brazil as P. cf. fernandezianus. This Brazilian collection was originally identified as P. beniensis Singer (1958: 285), a species in sect. Celluloderma, and was revised due to their observations of a euhymeniderm pileipellis mixed with clavate-fusiform and sphaeropedunculate elements, rather than an epithelial type pileipellis. In addition, their molecular analysis placed the specimen in sect. Hispidoderma. Due to an absence of macromorphological data, they related “ RSPF 330 ” to P. fernandezianus because of the shape and pigmentation of the pleurocystidia and cheilocystidia. The combination of larger, more utriform pleurocystidia, presence of sphaeropedunculate cells in the pileipellis, and molecular data separates “ RSPF 330 ” from the Vanuatu specimen. Interestingly, in part due to molecular and morphological data, “ RSPF 330 ” may be compared to the Vanuatu collections in the following section identified as P. rimosellus Singer in Singer & Digilio (1952: 262). Phylogenetic analysis of ITS data (Fig. 15 c) places the Vanuatu material of P. fernandezianus sister to a recently described species from Vietnam, P. ornatus E. F. Malysheva (2023: 20) (Malysheva et al. 2023). Both the Vanuatu specimen and P. ornatus share a superficial resemblance to the well-known species of P. umbrosus (Persoon) Kummer (1871: 98) and its allies. However, the two species can be separated due to some significant differences between them. Pluteus ornatus produces a much larger pileus (80 – 100 mm diam.) and stipe (70 – 90 × 6 – 13 mm). The Vanuatu material of P. fernandezianus has a stipe that is white overall with fine longitudinal gray fibrils, rather than the beigetoned stipe described in P. ornatus. Pluteus ornatus specimens also have distinctly marginate, serrate lamellae while those in the Vanuatuan P. fernandezianus have a whole margin. Micromorphologically, both specimens share the same shaped cystidia, but there are subtle significant differences. Pluteus ornatus has larger cheilocystidia (47 – 110 × 17 – 43), and pleurocystidia with 2 – 4 apical excrescences compared to the seldom observed single capitate pleurocystidia in the Vanuatu material. The latter difference may be significant, but it is noteworthy that variation in this form exists within known species of Pluteus or is easily overlooked as in the instance with P. chrysaegis. However, these traits in addition to phylogenetic distance in the analyses warrants treating them as separate taxa.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF8D5932FF7DFD5C1505FE25.taxon	diagnosis	Diagnosis: — Pluteus cf. haywardii from Aneityum is characterized by a grayish brown appressed-fibrillose, slightly marginally sulcate pileus, and a similarly colored stipe with a subbulbous base. Microcharacteristics include globose spores (6.7 × 6.1 µm), fusoid cheilocystidia, fusoid pleurocystidia, an ixo-cutis pileipellis with clustered, ascending clavate terminal elements, clavate caulocystidia, and an absence of clamp connections. Description: — Pileus 10 – 15 mm diam., convex, margin slightly sulcate; surface dull, somewhat moist, variably appressed-fibrillose typically fading towards the margin or faded at the disc; fibrils pallid tan to grayish brown (oac 702 – oac 704), surface cream-white. Context up to 2 mm thick, white. Lamellae free, moderately close with 2 – 3 tiers of lamellulae, thin, cream. Stipe 24 – 30 × 3 – 4 mm, central, cylindrical over a straight to subbulbous base, hollow; surface dull, dry, fibrous, cream to off-white, with minute streaks concolorous with the pileus surface, context white. Odor not observed. Taste not observed. Basidiospores 6 – 7 (– 8) × (5 –) 6 – 7 µm [x m = 6.67 ± 0.46 × 6.09 ± 0.44 µm, Q = 1 – 1.3, Q m = 1.1 ± 0.07, n = 50, s = 1], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 20 – 30 × 7 – 9 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 18 – 25 × 7 – 9 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 32 – 63 × 7 – 26 µm, narrowly fusoid to fusoid, or narrowly utriform, obtuse, hyaline, thin-walled. Pleurocystidia 36 – 63 (– 73) × 11 – 30 µm, narrowly to broadly fusoid-ventricose, or narrowly lageniform to narrowly utriform, obtuse, hyaline, thin-walled. Pileipellis an ixo-cutis of repent hyphae with ascending terminal elements embedded in a gelatinous matrix or gelatinized, composed of hyaline or with pale brown plasmatic pigment, non-incrusted, gelatinized or not, thin-walled, cylindrical hyphae, 12 - 20 µm diam.; terminal elements (55 –) 68 – 105 × 18 – 24 µm, typically in fascicles, suberect to erect, clavate to fusoid-ventricose, obtuse, with pale brown plasmatic pigment. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical hyphae, 3 – 26 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 14 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 12 µm diam .. Caulocystidia 22 – 46 × 8 – 20 µm, in fascicles or sometimes in trichoderm-like chains, clavate or rarely fusoid, obtuse, sometimes with one to three basal cells, hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on wood in subtropical montane primary broadleaf- Araucariaceae / Podocarpaceae rainforest containing Agathis macrophylla (Araucariaceae), Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Dendrocnide latifolia (Urticaceae), Ficus septica (Moraceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Geissois denhamii (Cunoniaceae), Hernandia moerenhoutiana (Hernandiaceae), Macaranga dioica (Euphorbiaceae), Podocarpus vanuatuensis (Podocarpaceae), Polyscias cissondendron (Araliaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Aneityum). Material examined: — VANUATU. Tafea Province: Aneityum, Noposjec, 20 ° 12.420 ′ S, 169 ° 46.795 ′ E, elev. 252 m, 11 December 2019, coll. J. A. del Rosario, JAD 346 (HAY). Notes: — Singer (1956) decided that Patouillard’s species, P. alborubellus (Montagne) Patouillard (1899: 196), from the Lesser Antilles was erroneously applied to the Montagne species Agaricus alborubellus Montagne (1854: 96) as he found the type to not represent a member of the genus Pluteus. Instead, Singer found Patouillard’s material to match his collection from Argentina, and decided to describe the taxon as P. haywardii Singer (1956: 147). Additional material has been reported from Martinique and Guadeloupe (Pegler 1983 a) and recollected in Argentina (Horak 1964, Singer 1961). The Vanuatu material matches closely with the descriptions of P. haywardii, but some morphological discrepancies with the type and very similar morphology to other species prevents a conclusive identification. Singer originally described the pleurocystidia and cheilocystidia together (Singer 1956, 1958), which are similar in shape but slightly smaller in size (37 – 55 × 13.7 – 29 µm equally) compared to the Vanuatu material. Singer also collected additional material close to the type locality, but only observed some of the spores to be more subglobose, with the overall majority still globose compared to the type, and illustrations of the pleurocystidia were provided to include more lageniform-shaped elements (Singer 1961). The type of P. haywardii also differs from the Vanuatu material by significantly smaller pileipellis elements (37 – 55 × 13.7 – 29 µm) and the presence of granules in the form of small fibrils on the pileus surface. Pegler’s material from the Lesser Antilles is more micromorphologically similar to the Vanuatu material, having similarly shaped and sized pileipellis elements and spores, and although the pleurocystidia and cheilocystidia match in shape and size, these are also larger than those of the type (Pegler 1983 a). The additional material reported from Horak (1964) has slightly larger spores and similarly sized pleurocystidia and cheilocystidia, however the pleurocystidia are differently shaped from the cheilocystidia, appearing to be more lageniform with a tapering apex compared to the type, Antillean, and Vanuatu material. Overall, there may be morphological variation within the species, but additional molecular data is necessary to determine this. While Singer describes small fibrils forming granules on the pileus surface, Pegler describes his material as containing squamules at the disc and throughout the pileus, while the surface of the Vanuatu material is glabrous overall, or at least minutely appressed-fibrillose. It must be acknowledged that the basidiomes of the Vanuatu material were not fully expanded when collected, so it is uncertain if expansion may have revealed a similar character or if this trait is important in the taxonomy of P. haywardii. In the ITS phylogenetic analysis (Fig. 15 a) the Vanuatu specimen falls in a poorly supported lineage (BS 70 %, PP 0.51) basal to other members of the supported P. semibulbosus (Lasch) Gillet (1876: 395) complex (BS 87 %, PP 1.0). On this branch, JAD 346 falls out with two collections from South Korea identified as P. semibulbosus (MF 437007, KF 668315). Pairwise analysis of overlapping ITS regions shows the Vanuatu sequence having 99.64 % similarity to the two South Korean specimens. Superficially, the two share similar basidiome stature, with the South Korean material having a wider pileus (10 – 25 mm diam.) (Park et al. 2017). Microscopically, these collections share similarly sized and shaped spores and similarly shaped cheilocystidia, pleurocystidia, and caulocystidia. All three cystidia types are similar in length, but the Vanuatu material generally has broader pleurocystidia and cheilocystidia. Based on micromorphology, JAD 346 is much more similar to the European material identified as P. semibulbosus compared to two other Vanuatu collections identified in this study as P. aff. semibulbosus (see below). Overall, JAD 346 differs in its colored stipe from European collections, and there is little to clearly separate this taxon morphologically from the current concept of P. semibulbosus. The basidiomes of the South Korean material are described with white to cream-colored stipes, but it is unclear if this character is enough to separate them as distinct species from P. semibulbosus. Due to morphological similarity and overlap among species within Singer’s (1986) stirps, Semibulbosus and the general P. semibulbosus complex, the identity of this Vanuatu species is inconclusive. Clear delimitations need to be established for P. semibulbosus to clearly separate this Vanuatu material. The same can be said for P. haywardii, as contemporary collections, molecular sampling, and re-examination are necessary to refine the concept for this species. Pluteus aquosus Singer (1956: 148) differs based on a white stipe, smaller spores, smaller cheilocystidia, and has subcapitate pleurocystidia (Singer 1956, 1958). There has been disagreement regarding the concept of Pluteus niveus Murrill (1917: 131). from the U. S. A. and the type has been re-examined in multiple studies. Smith and Stuntz (1958) and Banerjee and Sundberg (1993) assumed Singer’s (1956) description to be a composite of the type material and a different collection. Based on their concept, P. niveus clearly differs based on a white stipe, more ellipsoid spores, slenderer pleurocystidia, and smaller cheilocystidia (Banerjee & Sundberg 1993, Smith & Stuntz 1958).	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF8A593CFF7DFDE01274FED9.taxon	diagnosis	Diagnosis: — Pluteus macrocystidiatus from Futuna is characterized by a small, cream, convex, fibrillose, marginally eroded pileus, serrated lamellae, and a similarly ornamented and colored stipe with a bulbous base arising from a white tomentum. Microcharacteristics include subglobose to broadly ellipsoid spores (8.6 × 7.7 µm), rare sphaeropedunculate cheilocystidia, scattered fusiform to lageniform pleurocystidia, clustered and distinctly large broadly clavate caulocystidia, and an absence of clamp connections. Description: — Pileus 15 mm diam., convex, margin slightly sulcate, slightly eroded; surface hygrophanous, dry, appressed-fibrillose; fibrils off-white to cream (oac 815), densest at the disc, less dense towards the margin, underlying surface pale pink to pink-brown (oac 793). Context up to 2 mm thick, pale pink to pink-brown (oac 793). Lamellae free, crowded with 5 tiers of lamellulae, thin, pink-brown (oac 793), margin slightly serrate-eroded. Stipe 10 × 1.5 mm, central, cylindrical over a bulbous base arising from a white tomentum (upwards 2 mm from base), hollow; surface dry, dull, fibrous, flocculose at base; white fibrils over a tan (oac 795) surface, context white. Odor indistinct. Taste not observed. Basidiospores (7 –) 8 – 10 × (6 –) 7 – 9 µm [x m = 8.62 ± 0.75 × 7.63 ± 0.8 µm, Q = 1 – 1.5, Q m = 1.1 ± 0.1, n = 50, s = 1], subglobose to occasionally broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia not observed. Basidioles 16 – 22 × 8 – 10 µm, clavate, hyaline, thin-walled. Cheilocystidia 26 – 52 × 14 – 25 µm, rare, seldom forming a well-developed strip on the lamellar edge, sphaeropedunculate to broadly clavate, obtuse, hyaline, thin-walled. Pleurocystidia 42 – 76 × 8 – 22 µm, scattered, fusiform to lageniform, obtuse to truncate or capitate, hyaline, thin-walled. Pileipellis ambiguous (due to weathered nature of specimen), possibly a cutis, composed of cylindrical, hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 12 µm diam.; terminal elements 32 – 115 × 5 – 11 µm, repent or occasionally suberect, clavate to cylindro-clavate, obtuse. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical hyphae, 3 – 24 μm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 9 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 9 µm diam .. Caulocystidia 25 – 106 × 8 – 27 µm, common, solitary to clustered, clavate to broadly clavate, obtuse, hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary on decaying wood in subtropical montane primary broadleaf rainforest containing Ascarina diffusa (Chloranthaceae), Claoxylon fallax (Euphorbiaceae), Diospyros ferra (Euphorbiaceae), Dillenia biflora (Dilleniaceae), Ficus storckii (Moraceae), Geissois denhamii (Cunoniaceae), Metrosideros vitiensis (Myrtaceae), Phyllanthus myrianthus (Phyllanthaceae), Plerandra actinostigma (Araliaceae), Schefflera neoebudica (Araliaceae), and Syzygium chanelii (Myrtaceae), Vanuatu (Futuna). Material examined: — VANUATU. Tafea Province: Futuna, low slopes of Mount Tatafu from Natangi, 19 ° 31.309 ′ S, 170 ° 13.536 ′ E, elev. 281 m, 16 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 302 (HAY). Notes: — Unfortunately, sparse material and the poor condition of the Vanuatu specimen prevented a clear characterization of the pileipellis, which may be a cutis. Because of this missing character and closeness to a number of similar species, a provisional identification is proposed for this study. The small stature of the Vanuatu specimen suggests comparison to a number of Pluteus species. Pluteus delicatulus C. K. Pradeep & Vrinda (2006: 95) is a similarly small, fragile species from India, however it differs due to the darker basdiomes, smaller spores, smaller non-lageniform pleurocystidia, absence of caulocystidia, and an epithelioid pileipellis (Pradeep et al. 2006). Pluteus aquosus has similar micromorphology, but differs by lacking a serrate lamellar edge, having a pure white stipe lacking a bulbous base stipe, lacking white basal tomentum, having smaller spores, and ventricose cheilocystidia (Singer 1956, 1958, 1961). Pluteus albidus shares many morphological similarities, but differs slightly by its smaller subglobose spores, versiform cheilocystidia, smaller caulocystidia, and lacks serrate gill edges (Desjardin & Perry 2018). Pluteus espeletiae Singer (1961: 120) from Venezuela (Singer 1961) similarly shares a crenate gill edge, large spores (8 – 8.8 × 6.8 – 7.5 µm), and pleurocystidia shape, but differs due to having a scaly disc, ventricose cheilocystidia, pigmented cystidia, and lacking caulocystidia. ITS data phylogenetic analysis (Fig. 15 b) places P. macrocystidiatus with an undetermined Pluteus species from Taiwan (MK 041296) within the general plautus / longistriatus clade recognized by Justo et al. (2011 b). A pairwise comparison of the two aligned, overlapping ITS sequences reveals a 99.84 % similarity suggesting these may be conspecific. Currently, the Taiwanese material has not been studied and unfortunately morphological data is currently unavailable for comparison. Regardless, assuming these two are the same taxon there is a wide gap in a distribution between Taiwan and Vanuatu’s island of Futuna. Similarity between Taiwan’s range of northern subtropical climates to southern tropical and Vanuatu’s subtropical climate may explain the species’ preferred conditions. This species possibly occurs elsewhere throughout the Pacific, but incomplete regional records of this group combined with its general small stature suggest it is easily overlooked. The particular combination of the serrate lamellar edge, sparse cheilocystidia, and rather large spores and caulocystidia (hence the epithet macrocystidiatus) may be distinct enough to describe the species as new. It would be ideal to compare the Taiwanese specimen to the Futuna material and determine if these specific characters are shared consistently in both. Due to incomplete data and for the sake of the study, the Vanuatu specimen is tentatively identified with a nom. prov. pending further investigation of additional material.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF8A593CFF7DFDE01274FED9.taxon	description	Pluteus neochrysaegis Menolli & de Meijer in Menolli Jr., de Meijer & Capelari, Nova Hedwigia 100 (1 – 2): 135 (2014) [2015] (Figs. 27, 28) Diagnosis: — Pluteus neochrysaegis from Aneityum is distinguished by a grayish tan fading to white plano-convex pileus with a pellucid-striate margin and a rugose-venose uplifted white context disc. The bulbous based stipe is variably pallid tan fibrillose-flocculose. Microscopic characters include subglobose spores (6.3 × 5.6 µm), fusoid, thin to thick-walled acute cheilocystidia and obtuse pleurocystidia, an epithelioid hymeniderm pileipellis of pyriform cells with fusoid terminal cells over a cutis subpellis, fusoid-ventricose caulocystidia, pale grayish brown pigments throughout the cutis subpellis, stipitipellis, and caulocystidia, and an absence of clamp connections. Description: — Pileus 27 – 42 mm diam., broadly plano-convex with a broad slight central depression, slightly to broadly umbonate, margin minutely plicate in some; surface dull, dry, glabrous to appressed-fibrillose with minute exposed rivulose-pulverulent patches, disc absent or radially rugose-venose up to three-fourths the pileus width towards margin, veins splitting to expose and uplift the white context, margin pellucid-striate; surface overall pallid tan (oac 690, oac 710 – oac 711, oac 730 – oac 732) with slight dull yellowish gray (oac 723 – oac 725) tinges fading to white or grayish tan (oac 674 – oac 676) towards the margin. Context 1.5 – 3 mm thick, white. Lamellae free, crowded, with 3 – 4 tiers of lamellulae, thin, dull pink (oac 610 – oac 612). Stipe 20 – 50 × 3 – 5 mm, central, terete, cylindrical over a subbulbous to bulbous base, solid to hollow; surface dull, dry, longitudinally fibrillose-striate and / or minutely flocculose, pale tan (oac 653 – oac 655) over a white surface, context white. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 (– 8) × 5 – 7 µm [x mr = 6.22 – 6.5 × 5.52 – 5.62 µm, x mm = 6.3 ± 0.14 × 5.57 ± 0.1 µm, Q = 1.0 – 1.5, Q mr = 1.11 – 1.18, Q mm = 1.1 ± 0.14, n = 50, s = 4], subglobose to broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 20 – 35 × 6 – 8 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 12 – 26 × 5 – 8 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 35 – 83 × 6 – 25 µm, lageniform to broadly lageniform or fusoid-ventricose, obtuse, acute, or occasionally capitate, hyaline, thin to evenly or apically thick-walled (up to 3 µm thick) especially in larger cystidia. Pleurocystidia 35 – 90 × 15 – 25 (– 35) µm, scattered to common, fusiform to narrowly lageniform, obtuse or rarely mucronate, hyaline, thin to thick-walled (up to 3 µm thick) especially in larger cystidia; rarely 34 – 46 × 10 – 18 mm, fusoid-ventricose, acute or corniculate with 2 – 4 poorly developed hooks, hyaline, thin to thick-walled. Pileipellis an epithelioid hymeniderm with pileocystidia over a subpellis, majority of terminal elements 12 – 30 × 5 – 12 µm, sphaeropedunculate to clavate, obtuse or rarely mucronate, hyaline, non-incrusted, non-gelatinous, thin-walled; pileocystidia 28 – 55 (– 71) × 8 – 16 µm, scattered to abundant especially at the disc, fusiform to narrowly lageniform, obtuse, acute, infrequently capitate or rarely mucronate (up to 50 µm long), hyaline, thin to evenly or apically thick-walled especially in lageniform elements; subpellis a cutis of repent hyphae, composed of pale brown plasmatic pigmented, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 10 µm diam .. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical to inflated hyphae, 4 – 23 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 18 µm diam .. Stipitipellis a cutis, composed of hyaline or with patches of plasmatic pale brown pigment, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 14 µm diam .. Caulocystidia 20 – 62 × 6 – 16 µm, solitary or often clustered, lageniform to fusoid-ventricose, acute or rarely subcapitate, hyaline or with pale brown plasmatic pigment, thin to thick-walled especially in larger cystidia. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary to gregarious on decayed wood in subtropical montane primary broadleaf rainforest to cloud forest containing Balanops pedicellata (Balanopaceae), Diospyros sp. (Ebenaceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Ilex vitiensis (Aquifoliaceae), Melicope latifolia (Rutaceae), Metrosideros collina (Myrtaceae), Plerandra actinostigma (Araliaceae), Scaevola cylindrica (Goodeniaceae), Semecarpus tannaensis (Anacardiaceae), and Syzygium spp. (Myrtaceae) and montane primary broadleaf- Araucariaceae / Podocarpaceae rainforest containing Agathis macrophylla (Araucariaceae), Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Dendrocnide latifolia (Urticaceae), Ficus septica (Moraceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Geissois denhamii (Cunoniaceae), Hernandia moerenhoutiana (Hernandiaceae), Macaranga dioica (Euphorbiaceae), Podocarpus vanuatuensis (Podocarpaceae), Polyscias cissondendron (Araliaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Aneityum). Also known from Brazil (Paraná). Material examined: — VANUATU. Tafea Province: Aneityum, Anloulanelcau area, trail to Transect 11, 20 ° 13.066 ′ S, 169 ° 47.406 ′ E, elev. 188 m, 29 July 2017 coll. J. A. del Rosario, JAD 17 (HAY); Aneityum, Mount Inhetiji, lowland forest in former taro terraces close to Anecro, 20 ° 12.567 ′ S, 169 ° 51.102 ′ E, elev. 145 m, 12 December 2018, coll. J. A. del Rosario, JAD 244 (HAY); same location, 12 December 2018, coll. P. Dovo, JAD 245 (HAY); Aneityum, Anecro, footpath to river near Chief Nicolas’s house, 20 ° 12.490 ′ S, 169 ° 51.983 ′ E, elev. 76 m, 14 December 2018, coll. J. A. del Rosario, JAD 265 (HAY). Notes: — Pluteus neochrysaegis is currently known and originally described from Paraná state of Brazil (Menolli et al. 2015 a). The material collected from Aneityum Island fits well with the original description with minor caveats. Coloration in the pileus is slightly paler, albeit across collections variation occurs likely due to environmental conditions. In collection JAD 265, the distinct uplifted white context veins radiate from the disc, however multiple specimens in this collection show that the magnitude of this rugose-venose ornamentation varies as this is significantly reduced in the smallest basidiome and does not occur in the other collections. Menolli et al. (2015 a) distinguished P. conizatus (Berkeley & Broome) Saccardo from P. neochrysaegis by its pale yellow stipe, however this trait may not necessarily be consistent as the Vanuatu material has a similarly colored pale yellow stipe that varies but occurs across all specimens. Menolli et al. also discussed pileipellis similarity between P. neochrysaegis and P. chrysaegis, and distinguished P. neochrysaegis as different in having shorter pleurocystidia, dimorphic cheilocystidia, both lamellar cystidia types being pigmented, and ellipsoid spores. The Vanuatu material recognized as P. neochrysaegis shares similarly sized and shaped hyaline pleurocystidia compared to the Tafean collections and other regional accounts of P. chrysaegis. Between the Brazilian and Vanuatu material of P. neochrysaegis, the Brazilian specimen has smaller pleurocystidia (30 – 44 × 6.2 – 11.2 µm). The Vanuatu specimens lack pigmented cheilocystidia, which is present in the Brazilian material, but shares similarly sized and dimorphic thick-walled cheilocystidia. All the Vanuatu specimens of P. chrysaegis share this dimorphic variety of cheilocystidia with intermediate elements as well, so it is uncertain if this trait proposed by Menolli et al. as distinctive should be considered an exclusive feature of P. neochrysaegis. For the most part, the micromorphology between these species is nearly homogenous. One exception, that was also recognized by Menolli et al., could be the ellipsoid spores in P. neochrysaegis, while P. chrysaegis has typically subglobose spores. The primary means of distinguishing among these species would be through their pileus coloration as P. neochrysaegis has a dull grayish brown pileus fading to white without or with white veins, and P. chrysaegis typically has a brilliant to dull yellow pileus with brown veins.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF84593AFF7DFEE41283FAE0.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Tanna, Yanemari / Lighthouse and Mount Kuning area, 19 ° 37.602 ′ S, 169 ° 25.870 ′ E, elev. 286 m, 30 August 2018, coll. J. A. del Rosario, JAD 167 (HAY). Etymology: — ornato (L.) = ornate, cystidiatus (L.) = cystidia; in reference to the abundant apically ornamented cystidia on all tissues. Diagnosis: — Pluteus ornatocystidiatus from Tanna is characterized by a dark fading to pale tan areolate-squamulose disc, tan glabrous pileus with a pellucid-striate margin and a white stipe with tan floccules and a broadened base. Microcharacters include subglobose spores (6.1 × 4.9 µm), clavate sometimes mucronate cheilocystidia, lageniform mucronate or clavate pleurocystidia, a trichohymeniderm pileipellis comprised of lageniform, broadly clavate mucronate terminal elements that occasionally have thickened walls and brown pigmentation, fusoid mucronate caulocystidia, and an absence of clamp connections. Description: — Pileus 25 – 55 mm diam., convex to plano-convex, margin slightly sulcate or not; surface dull to pellucid-striate up to half-way from margin, hygrophanous, disc areolate-squamulose in expansion, glabrous with pulverulent patches towards the margin; disc and squamules dark tan (oac 646 – oac 647) fading to tan (oac 668 – oac 669) turning cream (oac 696 – oac 697) at the margin. Context up to 3 mm thick, pale pinkish brown. Lamellae free, close to crowded with 3 tiers of lamellulae. Stipe 30 – 55 × 4 – 6 mm, central, terete, cylindrical over a broadened base, hollow; surface pearlescent, dry, minutely flocculose or appressed-fibrillose, white overall with some tan floccules becoming most dense at the base. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 × 4 – 6 µm [x m = 6.08 ± 0.48 × 4.84 ± 0.5 µm, Q = 1 – 1.75, Q m = 1.26 ± 0.15 µm, n = 50, s = 1], subglobose to ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 16 – 24 × 4 – 7 µm, clavate, 4 - spored or 2 - spored, guttulate, hyaline, thin-walled, sterigmata 2 – 3 × 0.5 – 1 µm. Basidioles 15 – 28 × 5 – 10 µm, clavate, guttulate, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia 30 – 65 × 8 – 22 µm, clavate to narrowly lageniform or fusoid, obtuse or occasionally mucronate to subcapitate, hyaline, thin-walled. Pleurocystidia 30 – 68 × 8 – 32 µm, lageniform to fusoid-ventricose or narrowly utriform, mucronate with regular to irregular or strangulate apical projections, hyaline, thin-walled; some 50 – 78 × 25 – 36 µm, ovoid to broadly clavate, obtuse without apical projections, hyaline, thin-walled. Pileipellis a trichohymeniderm with pileocystidia, composed of a majority of cells 50 – 140 × 13 – 42 µm, clavate to broadly clavate, fusiform to fusoid-ventricose or lageniform, obtuse or frequently capitate or mucronate, typically with brown plasmatic pigment or occasionally hyaline, non-incrusted, non-gelatinous, thin-walled; pileocystidia 110 – 210 × 12 – 45, common, fusiform to fusoid, frequently mucronate with an elongated appendage (up to 85 µm long) or obtuse, with brown plasmatic pigment or occasionally hyaline, thin to evenly or apically thick-walled (up to 3 µm thick). Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, cylindrical hyphae, 5 – 28 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 20 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 4 – 12 µm diam .. Caulocystidia 30 – 120 × 13 – 22, clustered or scattered, clavate to broadly clavate or fusoid, capitate or mucronate, hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on decaying wood in subtropical lowland-montane secondary broadleaf- Podocarpaceae rainforest containing Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Cryptocarya wilsonii (Lauraceae), Ficus wassa (Moraceae), Ixora aneityensis (Rubiaceae), Podocarpus vanuatuensis (Podocarpaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna, Yanemari / Lighthouse and Mount Kuning area, 19 ° 37.602 ′ S, 169 ° 25.870 ′ E, elev. 286 m, 30 August 2018, coll. J. A. del Rosario, JAD 167 (HAY). Notes: — In comparison to P. ornatocystidiatus, the species P. heteromarginatus Justo (2011: 472) from the U. S. A. is close macromorphologically, but differs primarily by lacking a flocculose stipe. Micromorphologically it differs by having slightly smaller pleurocystidia, smaller cheilocystidia lacking apical appendages, narrower pileipellis terminal elements without thick walls or elongated apical appendages, and narrower caulocystidia (Justo et al. 2011 b). Pluteus aeolus (Berkeley & Broome) Saccardo (1887: 666), a tropical species from Sri Lanka, also has macromorphological similarities, but differs due to a lack of clavate or thick-walled pileipellis terminal elements, lack of mucronate cheilocystidia, and no pleurocystidia (Pegler 1986). Pluteus longistriatus Peck (Peck) (1835: 137) reported from North and South America is also superficially similar, but fundamentally differs in the absence of apical appendages on the pleurocystidia, cheilocystidia and caulocystidia, lacking apical appendages or thickened walls in the pileipellis terminal elements, and having less lageniform and non-mucronate caulocystidia (Menolli & Capelari 2010, Singer 1956, 1958). Based on ITS phylogenetic analysis (Fig. 15 a) P. ornatocystidiatus is placed on an unsupported branch (BS 39 %, PP 0.76) sister to the Italian species P. pulcherrimus Ferisin & Dovana (2019: 24). Pluteus pulcherrimus is macromorphologically much closer to the Vanuatu specimen, but this species differs by slightly smaller pleurocystidia, slightly smaller cheilocystidia lacking apical appendages, and generally larger caulocystidia that are apically acute (Ferisin & Dovana 2019). Importantly, P. pulcherrimus is distinguished by the presence of brown veins on the pileus disc, which are absent in the Vanuatu material.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF825942FF7DFAAC11F1F83D.taxon	description	= Pluteus pallidosquamulosus E. Malysheva, V. Malysheva, A. Alexandrova, & O. Morozova, Phytotaxa 461.2: 85 – 86 (2020) Diagnosis: — Pluteus rimosellus from Aneityum is characterized by a convex, slightly umbonate, marginally sulcate pileus with a grayish tan tomentose surface with patches exposing the off-white context and a venose-rugose or appressed squamulose disc composed of reddish brown pustules. The stipe is pale brown and minutely flocculose with a bulbous base. Microcharacters include broadly ellipsoid basidiospores with a mean size of 7.0 × 5.7 µm, fusoid-ventricose cheilocystidia and pleurocystidia both typically obtuse or infrequently with mucronate appendages, a euhymeniderm pileipellis with terminal elements comprised of pale brown pigmented, clavate-mucronate cells, sphaeropedunculate mucronate caulocystidia, and an absence of clamp connections. Description: — Pileus 12 – 45 mm diam., convex to campanulate expanding to hemispherical in age with a moderate umbo, disc finely to coarsely venose-rugose, margin sulcate; surface dull, dry, veins composed of pustulessubtomentum radiating and diminishing towards margin, appressed-fibrillose elsewhere with rimulose patches exposing the underlying off-white to gray context; pustules / tomentum dark reddish brown (oac 734 – oac 737) fading to pallid brown (oac 771 – oac 773) in age and away from the disc, fibrils and surface pallid grayish tan (oac 779 – oac 781 or oac 800 – oac 802). Context up to 4 mm thick, off-white to pale gray. Lamellae free, close with 2 tiers of lamellulae, thin, margin turning serrate in age, white turning dull pink (oac 767) in age. Stipe 20 – 48 × 3 – 5 mm, central, terete, cylindrical over a subbulbous to bulbous base, solid; surface dull, dry, glabrous or finely appressed-fibrillose to finely flocculose towards the apex, cream (oac 794 – oac 795) to white with pale brown (oac 771 – oac 773) fibrils and floccules, context white. Odor indistinct. Taste indistinct. Basidiospores 5 – 8 (– 9) × 5 – 8 µm [x mr = 6.64 – 7.0 × 5.37 – 6.2 µm, x mm = 7.02 ± 0.29 × 5.73 ± 0.42 µm, Q = 1 – 1.6, Q mr = 1.21 – 1.25, Q mm = 1.23 ± 0.02, n = 50, s = 3], subglobose to broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 20 – 30 (– 36) × 7 – 9 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 2 µm. Basidioles 13 – 28 × 7 – 12 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge heterogenous. Cheilocystidia 38 – 78 (– 92) × 14 – 28 (– 40) µm, in fascicles or forming a well-developed strip on the lamellar edge, versiform, clavate to broadly clavate, fusoid-ventricose, or seldom sphaeropedunculate, obtuse or in some collections mucronate with an appendage (up to 10 µm long) or digitate-capitate with 1 – 2 appendages or nodules, rarely with apical incrustations, hyaline, thin-walled. Pleurocystidia (38 –) 53 – 72 (– 86) × (10 –) 16 – 30 (– 38) µm, scattered to abundant, fusoid-ventricose to lageniform, obtuse or in some collections frequently mucronate with an appendage or digitate-capitate with 1 – 2 appendages / nodules, rarely with apical incrustations, hyaline, thin-walled. Pileipellis an intricate trichoderm to euhymeniderm over a cutis subpellis, composed of terminal elements 56 – 92 (– 115) × 14 – 26 µm, in erect to suberect fascicles, narrowly to broadly clavate or narrowly lageniform, obtuse, in some collections occasionally mucronate with an appendage (up to 17 µm long) or capitate with 1 – 2 nodules, with pale brown plasmatic pigment or hyaline, non-incrusted, non-gelatinous, thin or apically thick-walled (in one collection); subpellis a cutis, composed of hyaline or some with pale brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 12 µm diam .. Pileus trama composed of interwoven, hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 3 – 24 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 20 µm diam .. Stipitipellis a cutis, composed of hyaline or sometimes with pale brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 16 µm diam .. Caulocystidia 34 – 60 (– 73) × 8 – 19 (– 38) µm, scattered in fascicles, clavate to sphaeropedunculate, obtuse, in some collections frequently mucronate with an appendage (up to 22 µm long) or capitate with 1 – 2 nodules, hyaline or sometimes with pale brown plasmatic pigment, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary to gregarious on decayed wood in subtropical montane primary broadleaf- Araucariaceae / Podocarpaceae rainforest with Agathis macrophylla (Araucariaceae), Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Dendrocnide latifolia (Urticaceae), Ficus septica (Moraceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Geissois denhamii (Cunoniaceae), Hernandia moerenhoutiana (Hernandiaceae), Macaranga dioica (Euphorbiaceae), Podocarpus vanuatuensis (Podocarpaceae), Polyscias cissondendron (Araliaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Aneityum). Also known from Argentina, Brazil, Vietnam. Material examined: — VANUATU. Tafea Province: Aneityum, trail through Antowojon area, 20 ° 13.142 ′ S, 169 ° 47.788 ′ E, elev. 119 m, 28 July 2017, coll. J. A del Rosario & B. A. Perry, JAD 11 (HAY); Aneityum, Noposjec, 20 ° 12.710 ′ S, 169 ° 46.990 ′ E, elev. 192 m, 11 December 2019, coll. J. A. del Rosario, JAD 338 / 338 B (HAY); Aneityum, Noposjec, 20 ° 12.420 ′ S, 169 ° 46.795 ′ E, elev. 184 m, 11 December 2019, coll. J. A. del Rosario, JAD 343 (HAY). Notes: — Pluteus rimosellus was originally described by Singer from Argentina (Singer & Digilio 1952) and recently an isotype was re-examined and accompanied with a modern Brazilian collection (Menolli et al. 2015 a). Unfortunately, a recent re-examination of a paratype by Rodríguez (2024) found the specimen to be in poor condition and only spores were observable. Singer (1956) commented that P. fibrillosus Murrill (1917: 134), had a close relationship with both P. rimosellus and P. subfibrillosus Singer (1956: 187), but did not clarify how to distinguish between these taxa. Pluteus fibrillosus was described from Louisiana by Murrill (1917) and since then the holotype since then has been examined by multiple authors (Banerjee & Sundberg 1993, Menolli et al. 2015 a, Singer 1956, Smith & Stuntz 1958). The observations of Menolli et al. (2015 a) are consistent with previous examinations, including distinct incrustations in the pileipellis, but the same accounts were unable to confirm Singer’s observations of pigmented cystidia. Despite Singer’s observed similarities in P. fibrillosus to P. rimosellus and P. subfibrillosus, Menolli et al. treated P. fibrillosus as a separate species. In addition, Menolli et al. compared an isotype of P. rimosellus plus additional Brazilian material against the holotype of P. subfibrillosus, and due to similar micromorphology concluded that P. subfibrillosus should be considered a synonym of P. rimosellus. Extensive comparison of the protologues of both P. rimosellus and P. subfibrillosus reveals a wide range of macrocharacters that are also present and varied between the Vanuatu specimens. Specimens JAD 338 and JAD 338 - B were initially collected on the same piece of rotten wood; however, it was uncertain at the time if they were the same species. JAD 338 - B was composed of less mature and more venose fruiting bodies while JAD 338 had more mature, slightly paler basidiomes with one venose and a smaller one not (Fig. 31). Micromorphological comparison confirmed JAD 338 - B as being a less mature form of JAD 338. These more venose forms of the Vanuatu specimens place them closer to the descriptions of P. subfibrillosus (Singer 1956, 1958). The other Vanuatu specimens of this taxon, JAD 11 and JAD 343, have a pileus disc that is more appressed-squamulose to subtomentose (Fig. 32), and much more similar to P. rimosellus, which has not been described as venose (Singer 1958, Singer & Digilio 1952). Overall, consistent macrocharacters for this species would include the pileus with a sulcate margin, a grayish tan appressed-fibrillose rimulose surface with a disc being either squamulose to rugose-venose comprised of reddish brown subtomentum, and a white stipe covered with pale brown minute floccules. This would strengthen the case for Menolli et al. synonymizing P. subfibrillosus under P. rimosellus (Menolli et al. 2015 a). Based on both type descriptions of P. rimosellus and P. subfibrillosus plus the re-examinations by Menolli et al. (2015 a), the specimens from Vanuatu fit closer to the concept of P. rimosellus with some discrepancies. None of the Vanuatu material has pigmented pleurocystidia observed by previous authors. Both the cheilocystidia and pleurocystidia are slightly longer compared to the type collections being closer in size to the Brazilian collection made by Menolli et al. (2015 a), but this slightly varies between specimens. Otherwise, the size and shape of the globose to ellipsoid spores and the pileipellis elements fit well based on all other accounts, despite caulocystidia not being reported as in this material. The disc variation being either a reduced squamulose to a developed rugose-venose and the variously ornamented cystidia between specimens clearly point to a species with broad morphological variation. Comparisons among the Vanuatu specimens reveal minor differences in micromorphology regarding cystidia apical ornamentation, although these traits are not predominant among cell types. For example, the well matured basidiomes in JAD 338 had some pleurocystidia that were infrequently observed with mucronate-digitate apices, while the less matured basidiomes in collection JAD 338 - B occasionally has similar ornamentation on the cheilocystidia, and both share this on a minority of the pileipellis terminal cell apices. This particular trait would suggest comparison to P. jaffueli (Spegazzini) Singer (1954: 123) from Chile and Argentina, but this species differs primarily in having marginate lamellae and significantly larger pileipellis elements (66 – 150 × 13.8 – 30.8 µm) (Horak 1964, Singer 1954, 1956, 1958). In addition, a type of incrustation was sometimes observed on the cheilocystidia in JAD 338 and on the pleurocystidia of JAD 338 - B. Even the caulocystidia of JAD 338 had a higher degree of apical variation compared to the other collections. With regards to JAD 11 and JAD 343, none of these traits were observed, except the pileipellis elements of JAD 343 were infrequently observed with apically thickened walls. While these characteristics may not be considered consistent enough to be taxonomically informative it is still worth noting and does suggest a high level of micromorphological variation within this species. Despite this minor variation, these collections can be united through ITS molecular data and tentatively identified to P. rimosellus in combination with matching physical characters from the type descriptions and matching the overall shape and size range of the spores, cheilocystidia, pleurocystidia, and pileipellis arrangement and elements. In the phylogenetic analysis of ITS data (Fig. 15 b) a recently described Vietnamese species, P. pallidosquamulosus E. F. Malysheva & A. V Alexandrova (2020: 85), falls within the strongly supported branch with the Vanuatu specimens of P. rimosellus and the Brazilian P. cf. fernandezianus specimen. The study did not include ITS data for the Brazilian specimen nor was it mentioned or noted in the protologue (Malysheva et al. 2020). Pairwise analysis of overlapping ITS regions shows that the sequence for P. pallidosquamulosus ranges from 97.18 – 97.83 % similarity to the Vanuatu specimens, and 97.06 – 99.05 % similarity to the Brazilian sequence. As mentioned in the commentary of the Aneityum material identified as P. fernandezianus, Menolli et al. (2015 c) had revised collection “ RSPF 330 ”, initially identified as P. beniensis, to P. cf. fernandezianus due to an absence of macromorphological data. Microscopic comparison between the Vanuatu material and the observations provided by Menolli et al. (2015 c) match up well, however their material contained slightly longer pleurocystidia and pigmented pleurocystidia and cheilocystidia. Despite the absence of macromorphological data in “ RSPF 330 ”, similarity in micromorphology combined with ITS (JQ 065028) molecular data analysis places it with the Vanuatu specimens on a well-supported branch and suggests the identity of P. rimosellus. The micromorphology of P. pallidosquamulosus compared to the Vanuatu collections is practically a perfect match, with a minor exception of having slightly narrower pleurocystidia. Pluteus pallidosquamulosus even shares the minor variation seen throughout all the Vanuatu specimens, such as some pileipellis cells being slightly thick-walled, some cheilocystidia being apically papillate, or some pleurocystidia being subcapitate. The photo provided in the description bears a strong likeness to the Vanuatu specimens JAD 11 and JAD 343 suggesting similarity to P. rimosellus, and is dissimilar from the rugose-venose forms of the other collections and P. subfibrillosus (Figure 4 A, Malysheva et al. 2020). Comparing the type description of P. pallidosquamulosus to the type descriptions and re-examinations of P. rimosellus and P. subfibrillosus suggests they are the same species due to high morphological similarities (Menolli et al. 2015 a, Singer 1956, 1958, Singer & Digilio 1952). Therefore, it is unlikely P. pallidosquamulosus should be treated as a new species and may be better identified as P. rimosellus. Unfortunately, ITS data is unavailable for any of the types or additional collections of P. rimosellus or P. subfibrillosus, and this would be particularly useful in unifying these collections. However, this extensive literature comparison can confidently conclude this identity, and determines P. rimosellus as a morphologically variable species.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FF825942FF7DFAAC11F1F83D.taxon	diagnosis	Diagnosis: — Pluteus aff. semibulbosus from Tanna is characterized by a hygrophanous, pale pink to off-white glabrous, pellucid-striate pileus and a white stipe with a subbulbous base arising from a white tomentum. Microcharacters include subglobose basidiospores (8.0 × 7.1 µm), versiform cheilocystidia being broadly clavate to fusoid-ventricose, fusiform pleurocystidia, a euhymeniderm pileipellis consisting of clavate cells, clavate caulocystidia, and an absence of clamp connections. Description: — Pileus 20 – 34 mm diam., convex expanding to hemispherical in age with or without a slight central depression, sulcate up to half-way from margin, disc rugulose or smooth; surface dull at the disc when dry becoming pellucid-striate when moist, hygrophanous, dry to moist, glabrous when moist, to minutely appressed-fibrillose / subtomentose when dry; surface overall pale to dull pink (oac 669 / oac 597 – oac 599) typically turning white from the disc outwards in age or when drying, or white overall. Context 1 – 3 mm thick, white. Lamellae free, subdistant with 2 – 3 tiers of lamellulae, thin (1 – 1.5 mm thick), pale pink (oac 667 – oac 669). Stipe 25 – 30 × 3 – 4 mm, central, terete, cylindrical with a subbulbous base arising from a white tomentum, solid; surface shiny, dry, longitudinally fibrous, white to off-white, context white. Odor indistinct. Taste indistinct. Basidiospores 7 – 9 (– 10) × 6 – 9 µm [x mr = 7.84 – 8.14 × 7.06 µm, x mm = 7.99 ± 0.21 × 7.06 ± 0.02 µm, Q = 1 – 1.33, Q mr = 1.11 – 1.15, Q mm = 1.13 ± 0.01, n = 50, s = 2], globose to subglobose or rarely broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 19 – 30 × 6 – 12 µm, clavate to broadly clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 18 – 26 × 7 – 10 µm, clavate, guttulate, hyaline, thin-walled. Lamellar edge sterile. Cheilocystidia 36 – 80 × 15 – 28 µm, versiform, clavate to broadly clavate, fusoid-ventricose to narrowly lageniform, obtuse or short to long capitate, hyaline, thin-walled. Pleurocystidia 47 – 103 × 14 – 41 µm, fusiform to fusoid-ventricose, or narrowly lageniform to broadly utriform, obtuse or sometimes truncate, sometimes basally septate, hyaline, thin-walled. Pileipellis a euhymeniderm, composed of a majority of cells 25 – 110 × 6 – 28 µm, cylindro-clavate to broadly clavate or rarely fusoid-ventricose, obtuse, hyaline, non-incrusted, non-gelatinous, thin-walled. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 3 – 22 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 19 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 14 µm diam., commonly with excrescences. Caulocystidia 20 – 60 × 6 – 18 µm, scattered to clustered, cylindro-clavate to clavate, obtuse or rarely capitate, sometimes with basal septae, hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on decayed wood in subtropical lowland mixed-use agro tree garden and secondary broadleaf rainforest containing Bischofia javanica (Phyllanthaceae), Burckella obovata (Sapotaceae), Claoxylon gillisonii (Euphorbiaceae), Dendrocnide latifolia (Urticaceae), Didymocheton spp. (Meliaceae), Ficus spp. (Moraceae), Garcinia pseudoguttifera (Clusiaceae), Homolanthus nutans (Euphorbiaceae), Macaranga dioica (Euphorbiaceae), and Syzygium nomoa (Myrtaceae) and lowland-montane secondary broadleaf- Podocarpaceae rainforest containing Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Cryptocarya wilsonii (Lauraceae), Ficus wassa (Moraceae), Ixora aneityensis (Rubiaceae), Podocarpus vanuatuensis (Podocarpaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Tanna). Materials examined: — VANUATU. Tafea Province: Tanna, base of Mt. Kuning, 19 ° 37.602 ′ S, 169 ° 25.870 ′ E, elev. 286 m, 30 August 2018, coll. J. A. del Rosario, JAD 166 (HAY); Tanna, along banks of Numdretum River, 19 ° 37.482 ′ S, 169 ° 25.928 ′ E, elev. 267 m, 5 December 2018, coll. J. A. del Rosario, JAD 197 (HAY). Notes: — There has been disagreement among multiple authors about the species concept of P. semibulbosus, as some have described the pileipellis to consist of subglobose elements (Lange 1936, Orton 1960, 1986), while others recognize this taxon and others as conspecific within the P. plautus (Weinmann) Gillet (1876: 394) species complex (Vellinga 1990, Vellinga & Schreurs 1985). The original circumscription “ pileo carnosulo hemisphaerico obtuso atomoto-molli sulcato … ” (Fries 1838) was interpreted by Vellinga and Schreurs (1985) and Ferisin and Dovana (2019) to represent a species with a pileus cuticle comprised of particles, which when viewed microscopically is a trichodermal pileipellis containing elongated elements typical for sect. Hispidoderma. Both Vanuatu specimens fit this description, but their appearance slightly varies based on environmental conditions during collection. JAD 166 contains one basidiome with a pure white pileus and the other is an overall pinkish brown. The pilei of both collections are pellucid-striate, glabrous to minutely fibrillose / subtomentose and slightly rugulose at the disc (Fig. 34). JAD 197 had drier basidiomes, being a similarly colored pinkish brown around the pileus margin while the center is off-white and minutely fibrillose. Both specimens contain a pileipellis composed of elongated clavate terminal elements. The stipe of P. semibulbosus was originally described as “ … subtiliter fistuloso pubescente, basi bullato ” (Fries 1838), which could be interpreted as being fibrillose / pubescent with a bulbous base and a match to both Vanuatu specimens. Phylogenetic analysis by Justo et al. (Justo et al. 2011 b) determined the broad morphological concept of P. plautus by Vellinga and Schreurs (1985) comprising multiple species did not include P. semibulbosus, and concluded this taxon is a separate species requiring wider sampling for molecular and morphological distinction. For this study’s phylogenetic analysis of ITS data (Fig. 15 a), the two Vanuatu collections are positioned in a strongly supported clade representing sequences of P. semibulbosus (BS 95 %, PP 1.0) with low to moderately supported internal topology. The two Vanuatu specimens fall within a well-supported lineage (BS 98 %, PP 1.0) with a Japanese collection identified as P. aff. semibulbosus (HM 562090), a Spanish collection of P. cf. semibulbosus (KR 022020), a Slovenian (MK 534552), Vietnamese (OQ 732740), and two Italian (MK 446329, MK 446328) specimens identified as P. semibulbosus. Pairwise analysis of overlapping ITS regions of the two Vanuatu specimens compared to these sequences indicates a range of 99.11 – 99.82 % similarity to the previously mentioned taxa. Unfortunately, morphological data for the Japanese and Spanish collections is unavailable for comparison. Compared to the Italian / Slovenian collections, the Vanuatu specimens are distinguished macroscopically by having a pinkish brown pileus rather than white with a pale brown disc, and microscopically through larger spores, pleurocystidia and cheilocystidia, and more variable cheilocystidia with tapered to capitate apices (Ferisin & Dovana 2019). Compared to the Vietnamese material, the overall morphological descriptions fit quite well with each other (Malysheva et al. 2023). Phylogenetically, this lineage may be considered a separate species, but it is worth extensively comparing the Vanuatu specimens to the better-defined descriptions determined to be P. semibulbosus from South Korea (Park et al. 2017) and Turkey (Kaygusuz et al. 2019), which are placed in the adjacent lineages. Overall, the Vanuatu specimens’ microcharacters are also distinct in significantly larger spores, pleurocystidia and cheilocystidia compared to the South Korean and Turkish accounts. The versiform-shaped cheilocystidia of the Vanuatu specimens are closer to those in the Turkish material, while the others seem less variable and overall clavate. Pairwise analysis of the Vanuatu specimens to sequences of P. semibulbosus representative of the other two lineages shows 98.76 – 98.93 % similarity to those from Turkey (MK 123344, MK 123344) and 98.05 – 98.23 % similarity to those from South Korea (KF 668315, MF 437007). A separate Vanuatu collection made in Aneityum, collection JAD 346 as P. cf. haywardii (discussed above), is placed in a basal clade with the two South Korean collections. Between the Vanuatu collections of P. aff. semibulbosus and P. cf. haywardii, the main superficial differences are that the Vanuatu P. cf. haywardii has a white cap with tan streaks and a cream stipe. Microscopic differences include P. aff. semibulbosus having larger spores, larger pleurocystidia, and larger more versiform and lageniform cheilocystidia. Pairwise analysis of overlapping ITS data shows that the sequence from P. cf. haywardii is 97.7 – 97.90 % similar to the Vanuatu collections of P. aff. semibulbosus (JAD 166 and JAD 197). Because of these features combined with molecular evidence it is preferred to maintain them as separate units until wider sampling and in-depth study can better define species limits. Undoubtedly, there is some overlap between the specimens and the size range of the microcharacters in the Vanuatu specimens is likely of taxonomic importance. Further studies including a new type designation, intensive re-examination of existing specimens, and additional molecular data are necessary in order to clearly delimit P. semibulbosus and others within this broad complex. For now, the Vanuatu specimens will be treated as P. aff. semibulbosus.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFF9594AFF7DFF571287FA58.taxon	diagnosis	Diagnosis: — Pluteus velutinus from Aneityum is characterized by a brown pruinose pileus with pulverulent patches exposing a white context, and a tan fibrillose stipe with a subbulbous base. Microcharacters include subglobose spores (6.5 × 5.5 µm), clavate cheilocystidia, clavate or fusoid-ventricose pleurocystidia, a trichohymeniderm pileipellis comprised of fusoid terminal cells containing brown pigment, similarly pigmented clavate caulocystidia, and an absence of clamp connections. Description: — Pileus 35 mm diam., hemispherical; surface pruinose or somewhat pearlescent, dry, finely areolatereticulate with pulverulent patches exposing the underlying context; surface uniformly brown-toned (oac 722 – oac 723). Context 1.5 mm thick, white. Lamellae free, somewhat subdistant with 2 – 3 tiers of lamellulae, regular, dark pinkish brown (oac 659 – oac 660). Stipe 55 × 5 mm, central, terete, cylindrical over a subbulbous base, solid; surface pearlescent, dry, longitudinally fibrillose, overall tan (oac 653 – oac 655). Taste indistinct. Odor indistinct. Basidiospores (4 –) 5 – 7 (– 8) × (4 –) 5 – 7 µm [x m = 6.2 ± 0.82 × 5.8 ± 0.66 µm, Q = 1 – 1.33, Q m = 1.07 ± 0.09, n = 50, s = 1], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 15 – 20 (– 27) × 5 – 8 µm, clavate, 4 - spored, hyaline, with a guttule, thin-walled, sterigmata 1.5 – 4 × 0.5 – 1 µm. Basidioles 10 – 20 × 5 – 8 µm, clavate, hyaline, with a guttule, thin-walled. Lamellar edge sterile. Cheilocystidia 32 – 80 × 8 – 25 µm, clavate to broadly clavate, fusoid to narrowly utriform or sphaeropedunculate, obtuse, hyaline, thin-walled. Pleurocystidia 38 – 96 × 10 – 55 µm, clavate to ovoid or fusoid-ventricose to narrowly utriform, obtuse, seldom truncate or rarely with a mucronate appendage (up to 8 µm long), one observed with a median constriction, hyaline, thin to rarely thick-walled especially in larger ovoid elements. Pileipellis a trichohymeniderm, composed of a majority of cells 80 – 200 × 8 – 16 µm, clavate to cylindro-clavate mixed with 28 – 75 × 8 – 14 µm lageniform to fusoid or occasionally globose, obtuse or seldom capitate, with brown plasmatic pigment or hyaline, non-incrusted, non-gelatinous, thin-walled. Pileus trama interwoven, composed of hyaline or occasionally with brown plasmatic pigment, non-gelatinous, thin-walled, cylindrical to inflated hyphae, 3 – 17 (– 28) µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 24 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 24 µm diam .. Caulocystidia 25 – 48 (– 80) × 8 – 20 µm, abundant, solitary to clustered, clavate to cylindro-clavate or seldom fusoid-ventricose, obtuse, with brown plasmatic pigment or hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary on decayed wood in subtropical montane primary broadleaf- Araucariaceae / Podocarpaceae rainforest containing Agathis macrophylla (Araucariaceae), Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Dendrocnide latifolia (Urticaceae), Ficus septica (Moraceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Geissois denhamii (Cunoniaceae), Hernandia moerenhoutiana (Hernandiaceae), Macaranga dioica (Euphorbiaceae), Podocarpus vanuatuensis (Podocarpaceae), Polyscias cissondendron (Araliaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Aneityum). Also known from Asia (Japan, India, Mongolia, Russia, South Siberia, Vietnam), Europe (Italy), U. S. A. (Hawaii). Material examined: — VANUATU. Tafea Province: Aneityum, area around and within transect 11, 20 ° 12.622 ′ S, 169 ° 47.578 ′ E, elev. 294 m, 8 August 2017, coll. J. A del Rosario & B. A. Perry, JAD 53 (HAY). Notes: — The original description of P. velutinus Pradeep, Justo & Vrinda (2012: 871) is based on an Indian holotype and collections originating from Japan (Pradeep et al. 2012). Additional reports have extended the species’ distribution to Brazil (Menolli et al. 2015 c), Vietnam (Malysheva et al. 2020, 2023), across Russia (Malysheva et al. 2016), and to Italy and Slovenia (Ferisin & Dovana 2016, 2019). According to ITS data (MW 018888, MW 018907) in this study’s phylogenetic analysis (Fig. 15 b), the species may also occur in Hawaii, U. S. A .. The specimen from Aneityum matches well in comparison to previous descriptions of P. velutinus, but with some minor differences. The Vanuatu material diverges based on rarity of pleurocystidia with digitate apical projections (observed once) versus other descriptions that report this trait to be common. The absence of apical digitate projections on pleurocystidia appears to have been observed in recently described material from Vietnam by Malysheva et al. (2023), but they have also observed it as common in collected material from a previous study (Malysheva et al. 2020). However, this particular pleurocystidia ornamentation does not seem readily consistent based on line drawings from the protologue, as the Indian holotype lacks pleurocystidia with apical projections while the Japanese material’s pleurocystidia are ornamented (Fig. 3 e 2, Pradeep et al. 2012). According to the holotype description, the species is distinguished by this character, although they are rarer on the cheilocystidia and common on the pleurocystidia. Based on other reports of P. velutinus the frequency and variation of apical ornamentation does not appear to be only restricted to pleurocystidia, but occurs on other taxonomically informative structures, suggesting a high degree of morphological diversity within the species. The pileipellis terminal elements have been described as being irregularly shaped or having apical projections, as seen in material from Russia, Japan, and Italy, but less so in Brazilian, Indian, Vietnamese, or the Vanuatu material (Ferisin & Dovana 2016, Malysheva et al. 2016, 2020, 2023, Menolli et al. 2015 c, Pradeep et al. 2012). A lesser emphasized cystidia character has been described as “ undulating ” (Menolli et al. 2015 c) or “ strangulated ” (Ferisin & Dovana 2016) in caulocystidia of the Brazilian and Indian material, appearing as a median constriction in the Vanuatu specimen’s caulocystidia and pleurocystidia, and occurring in the cheilocystidia and pileipellis terminal cells of the Brazilian and Russian material respectively. Pleurocystidia with pale brown plasmatic pigment have been reported from Brazilian, Russian, and Vietnamese material, but not in the others nor the Vanuatu specimen. The Vanuatu specimen does share the presence of brown plasmatic pigment in caulocystidia and pileipellis hyphae, and this does appear consistent with all other accounts. Spore size and shape appears to vary across specimens, as the Vanuatu and Russian material appear to have more globose / subglobose spores while the others are more ellipsoid. Phylogenetic analysis of ITS data (Fig. 15 b) places the Vanuatu specimen in a weakly supported clade (BS 69 %, PP 0.93) with Vietnamese specimens of P. cf. velutinus (MT 611241, MT 611242) that subtends the other P. velutinus sequences within the stronger supported clade encompassing them. Pairwise analysis of overlapping regions of the ITS data show the Vietnamese specimen is 99.29 % similar to the Vanuatu sequence, whereas the Indian holotype is 97.26 % similar and the remaining sequences are 97.35 % similar. Malysheva et al. (2020, 2023) did not firmly identify their material due to it being phylogenetically different from the other P. velutinus specimens, and not having additional material from the Indochinese Peninsula region for comparison to propose a separate species. Malysheva et al. considered their material close to the Russian specimens based on spore size, but differing based on paler pileus color and cheilocystidia pigmentation. As the Vanuatu specimen is phylogentically closer to the Vietnamese specimen, it is worth noting that although spore size is similar to both the Russian and Vietnamese material (not typically exceeding a length of 7.5 µm according to Malysheva et al.) the pigmentation is absent in the cheilocystidia, and this character may not be enough to warrant a separate species. Early reports of P. velutinus considered it to be a pantropical species (Menolli et al. 2015 c) with the Japanese material being an exception, until additional records from temperate Italy and Russia surfaced (Ferisin & Dovana 2016, Malysheva et al. 2016). The species is better known now to be cosmopolitan as it has been found to occur in tropical, temperate, and subtropical climates across multiple continents and both hemispheres. Pradeep et al. (2012) and Menolli et al. (2015 c) note the difficulty in explaining this distribution pattern or distinguishing a center of origin for the species. This raises the question of how highly variable climates may have influenced the establishment of the species. Menolli et al. (2015 c) compared climatic data of the areas during the time of fructification for each collection among Japan, Brazil, and India and found similar relative humidity and slightly similar average temperatures between the Japanese and Indian collections, while the Brazilian material was collected during a tropical rainy season with much warmer temperatures. Similarly, the Vanuatu specimen was collected during the dry season of a subtropical climate country. The case for a new record from isolated islands such as Vanuatu may further complicate things or provide a stronger case for anthropic dispersal.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFF25956FF7DF9F911B6FC44.taxon	diagnosis	Diagnosis: — Pluteus aff. argentinensis from Tanna is characterized by a pileus with a fuliginous longitudinally-striate fibrillose surface and dark gray disc surface, and a gray longitudinally-striate fibrillose stipe with basal tan floccules. Microcharacters include subglobose basidiospores (6.4 × 6.1 µm), fusoid-ventricose cheilocystidia and pleurocystidia sometimes covered apically or entirely with mucilage, a cutis pileipellis with suberect dark brown pigmented fusoid terminal elements, and an absence of caulocystidia and clamp connections. Description: — Pileus 55 – 75 mm diam., convex expanding to plano-convex with a slight to deep (8 – 10 mm) central depression, margin slightly sulcate, eroded; surface pellucid-striate towards margin, dull elsewhere, dry, strongly longitudinally appressed-fibrillose or silky; fibrils fuliginous to ash brown (oac 624 – oac 627) densest and darkest at disc fading towards margin, underlying surface pallid tan. Context up to 2 mm thick, colored pallid tan (oac 661 – oac 662). Lamellae free, crowded with 3 – 4 tiers of lamellulae, thin, white to cream-white. Stipe 52 – 80 × 5 – 8 mm, central, terete, cylindrical sometimes arising from a white tomentum, hollow; surface pearlescent, dry, silky, off-white to gray overall, context off-white. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 (– 8) × 5 – 7 µm, [x mr = 6.36 – 6.5 × 6.02 – 6.18 µm, x mm = 6.43 ± 0.09 × 6.1 ± 0.11 µm, Q = 1 – 1.2, Q mr = 1.05 – 1.06, Q mm = 1.05 ± 0.01, n = 50, s = 2], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 24 – 38 (– 50) × 6 – 10 µm, clavate to cylindro-clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 20 – 25 × 5 – 8 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 25 – 80 × 10 – 24 µm, clavate to broadly clavate or fusoid-ventricose to narrowly utriform, obtuse or rarely umbonate, often with apical mucilage sometimes adhering spores that obscure view, hyaline, thin-walled. Pleurocystidia 42 – 100 (– 140) × 12 – 42 (– 50) µm, scattered, broadly clavate to fusoid-ventricose, narrowly lageniform, or sometimes broadly sphaeropedunculate, obtuse, some with apical or completely enveloped in mucilage sometimes with adhering spores that obscure view, hyaline, thin-walled. Pileipellis a cutis of repent hyphae, composed of dark brown plasmatic pigment or hyaline, non-incrusted, non-gelatinous, thin-walled, cylindrical hyphae, 4 – 16 µm diam.; terminal elements 40 – 90 (– 155) × 8 – 20 (– 35) µm, mostly repent becoming suberect in fascicles especially at the disc, cylindro-clavate to fusiform, obtuse or seldom subcapitate. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 4 – 22 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 5 – 16 µm diam .. Stipitipellis a cutis, composed of hyaline or infrequently with pale brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled hyphae, 8 – 16 µm diam .. Caulocystidia absent. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on rotted wood in subtropical coastal mixed-use agro tree garden and secondary littoral broadleaf forest containing Annona muricata (Annonaceae), Artocarpus altilis (Moraceae), Barringtonia asiatica (Lecythidaceae), Cocos nucifera (Arecaceae), Cordia dichotoma (Boraginaceae), Euodia hortensis (Rutaceae), Leucaena leucocephala (Fabaceae), Macaranga dioica (Euphorbiaceae), and Musa sp. (Musaceae) and secondary broadleaf rainforest containing Bischofia javanica (Phyllanthaceae), Burckella obovata (Sapotaceae), Claoxylon gillisonii (Euphorbiaceae), Dendrocnide latifolia (Urticaceae), Didymocheton spp. (Meliaceae), Ficus spp. (Moraceae), Garcinia pseudoguttifera (Clusiaceae), Homolanthus nutans (Euphorbiaceae), Macaranga dioica (Euphorbiaceae), and Syzygium nomoa (Myrtaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna, Yanemari, 19 ° 28.511 ′ S, 169 ° 25.616 ′ E, elev. 146 m, 30 August 2018, coll. J. A. del Rosario, JAD 171 (HAY); Tanna, Port Resolution near Tanna Horizon Bungalow, 19 ° 31.391 ′ S, 169 ° 30.371 ′ E, elev. 7 m, 16 August 2019, coll. J. A. del Rosario, M. Wahe & G. M. Plunkett, JAD 301 (HAY). Notes: — Pluteus argentinensis Singer (1958: 230) was originally described by Singer based on two collections from Argentina, one (Singer T 929) was initially identified as P. plautus (Singer & Digilio 1952) and the other (Singer T 2139) was designated as the holotype (Singer 1958). Since then, P. argentinensis has been reported from Mexico (Rodríguez & Guzmán-Dávalos 1999, 2001) and Brazil (Dias & Cortez 2013). According to Dias and Cortez, a report by Wright and Albertó (2002) from Buenos Aires may be misidentified based on the presence of clamp connections in that material. The Vanuatu specimens fit well within previous descriptions of P. argentinensis, however there are some discrepancies. Macroscopically, the Vanuatu material matches the holotype description, except that the pileus size is significantly larger than the type (25 – 35 mm diam.) and slightly larger compared to the other reports. In the original description, Singer described the pleurocystidia and cheilocystidia together by generalizing the size as “ 34 – 68 × 14 – 25 µm, mostly 42 – 54 × 14 – 19 µm ” and shape “ ventricose below and ampullaceous or mucronate above ”, and differentiated the cystidia on the lamellar edge by “ some ventricose-vesiculose or ampullaceous-subcapitate ” (Singer 1958). Singer also observed the presence of an inconspicuous resinous incrustation on these cystidia. Both lamellar cystidia in the Vanuatu material fit these criteria, except for being slightly larger. The presence of any type of incrustation / mucilage on cystidia was not reported from either the Mexican or the Brazilian material (Rodríguez & Guzmán-Dávalos 1999, 2001, Dias & Cortez 2013). Compared to the Vanuatu collections, the Mexican material would be closer in pleurocystidia and cheilocystidia shape variety (Rodríguez & Guzmán-Dávalos 1999), while the Brazilian material is similar in size, but the pleurocystidia were described only as ventricose and lack lageniform or clavate elements (Dias & Cortez 2013). The orientation of the pileipellis is not clearly categorized in the original description of P. argentinensis, and Singer only provided measurements, an illustration and emphasized the terminal elements as “ fusoid to ventricose with strongly attenuate apex ” (Singer 1958). Singer’s collection T 929, originally identified as P. plautus, described the pileipellis as a trichoderm with the majority of the elements depressed (Singer & Digilio 1952). Pileipellis interpretation has varied in concepts of P. argentinensis as Rodríguez and Guzmán-Dávalos (1999) described their material as a trichoderm and suberect, while Dias and Cortez described “ filamentous and elongated hyphae ” providing a photo similar to a repent cutis with terminal elements appearing as ascending (Fig. 4, Dias & Cortez 2013). Rodríguez and Guzmán-Dávalos did re-examine a portion of the holotype, but due to the poor condition of the material were unable to measure elements of the pileipellis and could only provide spore measurements (Rodríguez & Guzmán-Dávalos 2001). Singer placed P. argentinensis in his morphological stirps Fuliginosus, which he characterized by the pileipellis terminal cells being subacute or acuminate-subacute and part of a trichoderm (Singer 1958, 1986). Regarding the Vanuatu material, the pileipellis is overall a cutis with the terminal elements sometimes turning to erect clusters with the shape and size of the terminal elements fitting well with all previous described material, but the ambiguity of the pileipellis arrangement from the protologue requires clarity. Singer did not originally describe the shape of the spores, but the Vanuatu material matches in size and matches the shape and size in the other material. The absence of caulocystidia was noted in the Mexican material (Rodríguez & Guzmán-Dávalos 1999), but other authors omitted its presence or absence. Overall, the Vanuatu specimen’s pleurocystidia and cheilocystidia closely resemble those in the Mexican material, while the Brazilian material lacks clavate cystidia. Both the Mexican and Brazilian material lack mucilage / incrustation on their cystidia, but this character is shared with the holotype according to the original description. Interestingly, the accompanying picture of the Brazilian specimen bears a resemblance to the Vanuatu material (Fig. 1, Dias & Cortez 2013), and the pileipellis shares some similarity as well. The slight difference in cystidia shape from the Brazilian material may be just minor variation and both might be the same species, but molecular data is unavailable for further confirmation. Regardless, clarification of pileipellis arrangement and molecular sampling would be preferred to confirm this material as P. argentinensis. Observations of the presence of mucilage / incrustation and the arrangement of the pileipellis in the other material would also be necessary to confirm their identities and strengthen the concept of P. argentinensis. In agreement with Menolli and Capelari (2016), a revision of the holotype is necessary to refine the concept of P. argentinensis and ideally a re-examination of these collections would unite them. A number of species from Singer’s morphological stirps (Singer 1986), such as Diptychocystis, Fuliginosus, or Spilopus, resemble the Vanuatu specimens, but their micromorphological characters can subtly distinguish them. Pluteus diptychocystis Singer (1954: 123) was described from Argentina (Singer 1954) and has been reported from Chile (Singer 1969) and Brazil (Menolli & Capelari 2016). Macromorphologically, P. diptychocystis differs in having a tomentose to squamulose pileus and micromorphologically differs by having slightly larger ellipsoid spores (6.8 – 9.6 × 5.3 – 7 µm), more lageniform or “ ampullaceous with broad neck ” and less cylindro-clavate pleurocystidia and cheilocystidia, and more apically rounded pileipellis terminal elements (Singer 1954, 1956, 1958, Menolli & Capelari 2016). Pluteus striatocystis Pegler (1977: 268) was originally described from east Africa (Pegler 1977) and reported from re-identified material from Brazil (Menolli et al. 2015 a). This species primarily differs micromorphologically with more ellipsoid spores, smaller pleurocystidia (40 – 70 × 15 – 25 µm) with a characteristic distinct striate collar, smaller cheilocystidia (36 – 46 × 11.2 – 20 µm) absent of mucilage / incrustation, and longer pileipellis terminal elements (– 214 × 17.5 µm) (Pegler 1977, Menolli et al. 2015 a). The Bolivian P. pluvialis Singer (1958: 234) may be interpreted as similar by sharing a pubescent “ margined ” bulbous base, although the Vanuatu material here is described as cylindrical with a white tomentum (Singer 1958). Regardless, P. pluvialis would differ through being smaller in stature, having granular punctations on the pileus, slightly smaller cheilocystidia (40 – 55 × 7 – 21 µm), smaller pleurocystidia, and larger pileipellis elements (82 – 165 × 16.5 – 19.5 µm) with more attenuate apices.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFEE5953FF7DFC0312C1FCEA.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Tanna, Yanemari, 19 ° 38.294 ′ S, 169 ° 25.568 ′ E, elev. 146 m, 30 August 2018, coll. J. A. del Rosario, JAD 168 (HAY). Etymology: — refers to morphological similarities to P. eugraptus. Diagnosis: — Pluteus eugraptoides from Tanna is characterized by a pale brown hygrophanous pileus with maroon-brown veins radiating from the disc, and a gray stipe with a subbulbous base. Microcharacteristics include subglobose spores (6.7 × 5.5 µm), fusoid-ventricose, cheilocystidia and pleurocystidia, a euhymeniderm pileipellis composed of brown pigmented clavate or sphaeropedunculate, sometimes mucronate cells, clavate or fusoid-ventricose caulocystidia, and an absence of clamp connections. Pluteus eugraptoides closely resembles P. eugraptus (Berkeley & Broome) Saccardo (1887: 678), but fundamentally differs by lacking marginate lamellae. Description: — Pileus 15 – 35 mm diam., hemispherical to plano-convex and papillate; surface dull becoming pulverulent-pellucid-striate, dry, glabrous, disc venose-rugulose, radiating up to one-half of pileus towards margin; veins / wrinkles maroon-brown (oac 621 – oac 623) or concolorous with the surface, surface dull brown (oac 722) fading to pale tan (oac 675 – oac 676) towards the margin. Context 3 mm thick, pale tan. Lamellae free, close with 2 – 3 tiers of lamellulae, slightly thick (up to 2 mm thick), tan (oac 675 – oac 676). Stipe 25 – 35 × 3 – 5 mm, central, terete, cylindrical over a subbulbous base, hollow; surface dull, dry, silky, gray to pale tan (oac 675 – 676), context white. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 (– 8) × 5 – 6 µm [x m = 6.71 ± 0.79 × 5.51 ± 0.49 µm, Q = 1 – 1.6, Q m = 1.22 ± 0.15, n = 50, s = 1], subglobose or seldom broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 22 – 28 × 5 – 8 µm, clavate to cylindro-clavate, 4 - spored or rarely 2 - spored, hyaline, guttulate, thin-walled, sterigmata 1.5 – 3 × 0.5 – 1 µm. Basidioles 16 – 28 × 5 – 8 µm, clavate to cylindro-clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 32 – 46 (– 56) × 8 – 14 (– 20) µm, abundant, often clustered, clavate or occasionally lageniform to fusoid-ventricose, obtuse, hyaline, thin-walled. Pleurocystidia (25 –) 40 – 65 (– 72) × 12 – 20 µm, lageniform to fusoid-ventricose, obtuse, hyaline, thin-walled. Pileipellis a euhymeniderm to epithelioid hymeniderm, composed of a majority of cells 25 – 50 × 10 – 22 µm, clavate to sphaeropedunculate, obtuse, sometimes mucronate (up to 5 µm long) or rarely nodulose-capitate with 1 – 2 nodules, with brown plasmatic pigment or sometimes hyaline, non-incrusted, non-gelatinous, thin-walled. Pileus trama interwoven, composed of hyaline, non-incrusted, non-gelatinous, thin-walled, clavate to inflated hyphae, 4 – 25 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 5 – 14 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 5 – 15 µm diam .. Caulocystidia 30 – 70 × 13 – 25 µm, clustered to solitary, fusoid-ventricose to clavate, obtuse, hyaline or with brown plasmatic pigment, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on rotted wood in subtropical lowland mixed-use agro tree garden and secondary broadleaf rainforest containing Bischofia javanica (Phyllanthaceae), Burckella obovata (Sapotaceae), Claoxylon gillisonii (Euphorbiaceae), Dendrocnide latifolia (Urticaceae), Didymocheton spp. (Meliaceae), Ficus spp. (Moraceae), Garcinia pseudoguttifera (Clusiaceae), Homolanthus nutans (Euphorbiaceae), Macaranga dioica (Euphorbiaceae), and Syzygium nomoa (Myrtaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna, Yanemari, 19 ° 38.294 ′ S, 169 ° 25.568 ′ E, elev. 146 m, 30 August 2018, coll. J. A. del Rosario, JAD 168 (HAY). Notes: — Pluteus eugraptoides has some macroscopic features similar to multiple species, however there are microscopic differences. Pluteus variipes Singer (1956: 218) was collected from Argentina (Horak 1964, Singer 1956, 1958) and Bolivia (Singer 1956, 1958) and has a similarly colored pileus, but is overall non-venose, has smaller spores and slightly larger pleurocystidia (34.7 – 67 × 16 – 37.5 µm). The Mexican species P. neotropicalis Rodríguez-Alcántar (2008: 274) is also superficially similar, but differs in having slender fusoid cheilocystidia with a long cylindrical projection, narrow subcylindrical pleurocystidia, and narrow fusoid pileipellis elements (Rodri ́ guez et al. 2008). Pluteus chusqueicola Horak (1964: 180) from Argentina is similar in stature, and shares capitate / mammillate pileipellis elements, but these cells tend to have slightly thickened walls and this species also has slightly larger pleurocystidia (60 – 75 × 16 – 30 µm) (Horak 1964).	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFEB5950FF7DFC931470FC98.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Aneityum, trail through Antowojon area, 20 ° 13.142 ′ S, 169 ° 47.788 ′ E, elev. 119 m, 28 July 2017, coll. J. A. del Rosario & B. A. Perry, JAD 12 (HAY). Etymology: — Named in honor of the Lalep family and for their contributions of the language and natural knowledge of Aneityum to the Plants mo Pipol blong Vanuatu project. In memory of Titya Kelly Lalep, who was one of the earliest contributors. Diagnosis: — Pluteus lalepiorum from Aneityum is characterized by a hygrophanous, cream colored pileus with sooty brown floccules at the disc and a white stipe typically with similar floccules towards the base. Microcharacters include subglobose basidiospores (6.1 × 5.5 µm), fusoid-ventricose thick-walled cheilocystidia and pleurocystidia with mucilage coating some pleurocystidia, a cutis pileipellis with fragmented erect filiform brown pigmented terminal elements, similarly shaped and pigmented caulocystidia, and an absence of clamp connections. Description: — Pileus 40 – 45 mm diam., hemispherical to plano-convex with an umbo, some slightly centrally depressed, margin entire or undulate; surface dull turning pellucid-striate at margin, hygrophanous, appressed-fibrillose turning glabrous at margin, disc finely flocculose; floccules and fibrils sooty brown (oac 778 – oac 780) dense at disc, diminishing towards margin, fibrils turning cream to off-white with minute sooty brown streaks, surface pale off-white. Context 5 mm thick, white to off-white. Lamellae free, crowded with 3 tiers of lamellulae, thin, pallid tan to pale pink (oac 709 – oac 711). Stipe 25 – 40 × 2.5 – 4 mm, central, terete, cylindrical over a bulbous base, solid; surface dull, dry, fibrous, some finely flocculose towards the base, white overall with sooty brown floccules, context white, arising from a white tomentum or not. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 × 5 – 7 µm [x m = 6.1 ± 0.54 × 5.42 ± 0.57 µm, Q = 1.0 – 1.4, Q m = 1.13 ± 0.13, n = 50, s = 1], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 16 – 25 × 6 – 8 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 11 – 19 × 6 – 8 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 30 – 78 × 8 – 16 µm, clavate to fusoid-ventricose, obtuse or mucronate, hyaline, thin to thick-walled (up to 2 µm thick). Pleurocystidia 40 – 80 × 11 – 30 µm, fusoid-ventricose to narrowly lageniform or narrowly utriform, obtuse or sometimes capitate-truncate, some with apical lateral mucilage sometimes with adhering spores that obscure view, hyaline, thin to thick-walled. Pileipellis a cutis of repent hyphae with fragmented erect terminal elements (pileocystidia), composed of hyaline or brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled, cylindrical hyphae, 3 – 11 µm diam.; pileocystidia 30 – 110 × 5 – 10 µm, repent to erect, solitary to clustered in fascicles especially at the disc, filiform to fusoid, acute, obtuse or subcapitate, sometimes with one to multiple basal cells, typically with brown plasmatic pigment or occasionally hyaline. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate to inflated hyphae, 3 – 25 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 16 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 4 – 18 µm diam .. Caulocystidia 50 – 110 × 6 – 16 µm, similar to pileipellis terminal elements, clustered to solitary, filiform to narrowly lageniform, acute, obtuse or sometimes capitate, some with one to multiple basal cells, with brown plasmatic pigment or sometimes hyaline, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on decayed wood in subtropical montane primary broadleaf- Araucariaceae / Podocarpaceae rainforest containing Agathis macrophylla (Araucariaceae), Balanops pedicellata (Balanopaceae), Calophyllum neoebudicum (Calophyllaceae), Dendrocnide latifolia (Urticaceae), Ficus septica (Moraceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Geissois denhamii (Cunoniaceae), Hernandia moerenhoutiana (Hernandiaceae), Macaranga dioica (Euphorbiaceae), Podocarpus vanuatuensis (Podocarpaceae), Polyscias cissondendron (Araliaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Aneityum). Material examined: — VANUATU. Tafea Province: Aneityum, trail through Antowojon area, 20 ° 13.142 ′ S, 169 ° 47.788 ′ E, elev. 119 m, 28 July 2017, coll. J. A. del Rosario & B. A. Perry, JAD 12 (HAY). Notes: — The distinctly thick-walled cystidia are unusual for members of sect. Celluloderma suggesting immediate comparison to only one other known species with this trait in the section: P. crassocystidiatus Menolli & de Meijer (2014: 114). This Brazilian species is known only from the protologue (Menolli et al. 2015 a) and compared to P. lalepiorum shares similarly shaped thick-walled pleurocystidia and cheilocystidia that contain apical mucilage, but has much longer cheilocystidia (44 – 110 × 11.2 – 24 µm). The pileipellis in P. crassocystidiatus is also different, being a euhymeniderm of smaller clavate-vesiculose cells (23 – 41 × 17.5 – 24 µm). Pluteus crassocystidiatus is also not known to have caulocystidia and has a different colored olive brown to yellowish brown pileus.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFE8595EFF7DFCA411C7F7F5.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Aneityum, lowland in former taro terraces, Mount Inhetiji, 20 ° 12.531 ′ S, 169 ° 51.071 ′ E, elev. 116 m, 12 December 2018, coll. J. A. del Rosario, JAD 239 (HAY). Etymology: — Named in honor of Presley Dovo for his extensive contributions to the Plants mo Pipol blong Vanuatu project as far back as the earliest 2006 expeditions on the island of Santo. Diagnosis: — Pluteus presleyi from Aneityum is characterized by a light tan pileus covered with gray fibrils and floccules-spinules at the disc spreading outwards, and a cylindrical white stipe. Microcharacteristics include subglobose basidiospores (5.7 × 5.2 µm), fusoid-ventricose cheilocystidia, fusoid-ventricose pleurocystidia occasionally apically nodulose, a cutis pileipellis with suberect clustering clavate or filiform brown pigmented terminal elements, an absence of caulocystidia, and a lack of clamp connections. Description: — Pileus 20 – 30 mm diam., convex with a slight umbo, with or without a slight central depression; surface dull, dry, densely longitudinally appressed-fibrillose turning into erect clusters and splitting to expose the context underneath, disc rugose or pustulate-spinulose to floccose; fibrils and pustules / spinules / floccules pallid gray-brown (oac 723 – oac 725), underlying surface isabelline / grayish brown (oac 730 – oac 732). Context 1 mm thick, white. Lamellae free, subdistant to close with 1 – 2 tiers of lamellulae, thin, dark tan (oac 660 / oac 667). Stipe 20 – 40 × 3 – 4 mm, central, terete, cylindrical, solid; surface pearlescent, dry, silky, white, context white. Odor indistinct. Taste indistinct. Basidiospores 5 – 7 × 4 – 6 µm [x mr = 5.58 – 5.86 × 5.14 – 5.28 µm, x mm = 5.72 ± 0.18 × 5.21 ± 0.09 µm, Q = 1.0 – 1.5, Q mr = 1.08 – 1.1, Q mm = 1.1 ± 0.02, n = 50, s = 2], globose to subglobose, rarely broadly ellipsoid, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 14 – 22 × 4 – 6 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 13 – 22 × 4 – 8 µm, clavate, hyaline, guttulate, thin-walled. Cheilocystidia (21 –) 28 – 46 × 8 – 17 (– 24) µm, clavate to fusoid-ventricose, obtuse or rarely capitate (observed once), hyaline, thin-walled. Pleurocystidia 44 – 70 × 9 – 18 (– 28), common to scattered, lageniform to fusoid-ventricose, obtuse to umbonate or occasionally nodulose-capitate with 1 – 2 nodules, hyaline, thin-walled. Pileipellis a cutis with ascending terminal elements typically in fascicles, composed of cylindrical, with pale brown plasmatic pigment or sometimes hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 20 µm diam.; terminal elements 24 – 125 × 2 – 30 µm, ellipsoid to broadly clavate, cylindro-clavate or occasionally filiform, obtuse to somewhat tapering, seldom subcapitate or with a medial nodule. Pileus trama interwoven, composed of hyaline, non-gelatinous, thin-walled, clavate hyphae, 3 – 26 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 2 – 12 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 16 µm diam .. Caulocystidia absent. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary on decaying wood in subtropical montane primary broadleaf rainforest to cloud forest containing Balanops pedicellata (Balanopaceae), Diospyros sp. (Ebenaceae), Ficus smithii (Moraceae), Garcinia platyphylla (Clusiaceae), Ilex vitiensis (Aquifoliaceae), Melicope latifolia (Rutaceae), Metrosideros collina (Myrtaceae), Plerandra actinostigma (Araliaceae), Scaevola cylindrica (Goodeniaceae), Semecarpus tannaensis (Anacardiaceae), and Syzygium spp. (Myrtaceae), Vanuatu (Aneityum). Material examined: — VANUATU. Tafea Province: Aneityum, lowland in former taro terraces, Mount Inhetiji, 20 ° 12.531 ′ S, 169 ° 51.071 ′ E, elev. 116 m, 12 December 2018, coll. J. A. del Rosario, JAD 239 (HAY); Aneityum, lowland in former taro terraces, Mount Inhetiji, S 20 ° 12.567 ’, E 169 ° 51.206, elev. 140 m, 12 December 2018, coll. J. A. del Rosario, JAD 251 (HAY). Notes: — Pluteus presleyi is comparable to several species that are macromorphologically superficially similar. The Sri Lankan P. spilopus tends to be larger in stature (4 – 10 cm), has non-lageniform pleurocystidia and more obtuse and non-tapering pileipellis terminal elements (Pegler 1986). Another Sri Lankan species, P. escharites (Berkeley & Broome) Saccardo (1887: 670) is similar in stature, but differs based on lacking pleurocystidia, and having a disrupted trichoderm pileipellis with fundamentally different fusoid terminal elements (Pegler 1986). Pluteus hispidilacteus Horak (2008: 20) from New Zealand has a somewhat similar pileus, but differs in the hispid stipe, absent pleurocystidia, nonovoid and non-capitate pileipellis terminal elements, and the presence of caulocystidia (Horak 2008). The European species P. hispidulus (Fries) Gillet (1887: 391) is similar in stature with a slightly more squamulose pileus surface, but differs microscopically in rare to absent pleurocystidia, narrowly clavate cheilocystidia, and non-capitate and non-filliform pileipellis terminal elements (Kühner & Romagnesi 1956, Vellinga & Schreurs 1985). The Chinese P. squarrosus Iqbal Hosen & T. H. Li (2019: 3) has similar pileus coloration, somewhat similar surface characteristics and similarly shaped cheilocystidia and pleurocystidia, but differs in having a more squamose-areolate pileus surface, larger pleurocystidia (45 – 80 × 13 – 28 µm), having caulocystidia, and a trichoderm pileipellis (Hosen et al. 2019). Phylogenetic analysis of the ITS data (Fig. 37 e) resolves P. presleyi in a basal grade to sect. Celluloderma. The general cutis pileipellis and non-metuloid lamellar cystidia would conform with the current concept of sect. Celluloderma. Interestingly, among the variable elongated clavate and filiform pileipellis cells there are occasionally terminal elements that are chains consisting of short cylindrical cells, ending in short ellipsoid cells. These chains almost resemble epithelioid cells and are perhaps similar to a kind of intermediate form between the cells typical in a hymeniderm or epithelium. Nevertheless, the morphological differences and phylogenetic placement are enough to recognize this species as new.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFE5595AFF7DFF54124BF9A4.taxon	diagnosis	Diagnosis: — Based on material from Tanna, P. aff. riberaltensis var. missionensis is characterized by an ash brown fibrillose-rimulose pileus with a squamulose disc, and a white basally ash gray flocculose stipe with a subbulbous base. Microcharacteristics include globose basidiospores with a mean size of (5.7 × 4.6 µm), lageniform capitate cheilocystidia, fusoid-ventricose pleurocystidia without or with mucilage, a euhymeniderm-trichoderm pileipellis with brown pigmented lageniform terminal cells overlying a cutis subpellis, narrowly fusiform caulocystidia, and an absence of clamp connections. Description: — Pileus 28 – 35 mm diam., convex with a slight umbo with or without a slight central depression, margin slightly sulcate or not; surface dull, dry, densely appressed-fibrillose, disc squamulose-areolate turning radially rimose; squamules, pustules and fibrils ash brown (oac 723 – oac 725) densest and darkest at disc, fading to brown-gray (oac 701 – oac 704) towards the margin with minute streaks of the underlying white context. Context 2 – 3 mm thick, white. Lamellae free, close, with 2 – 3 tiers of lamellulae, regular, off-white, turning pale pink (oac 760) in maturity. Stipe 42 – 50 × 3 – 5 mm, central, cylindrical over a subbulbous base, hollow; surface pearlescent, dry, fibrous, minutely flocculose at the base, surface white to off-white, floccules pale tan (oac 760), context white. Odor indistinct. Taste indistinct. Basidiospores 5 – 6 × 4 – 6 µm [x m = 5.66 ± 0.47 × 4.62 ± 0.56 µm, Q = 1 – 1.5, Q m = 1.24 ± 0.17, n = 50, s = 1], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 23 – 32 × 6 – 8 µm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 µm. Basidioles 18 – 23 × 5 – 8 µm, cylavate to cylindro-clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 30 – 64 × 8 – 13 µm, fusiform to fusoid or clavate, obtuse or capitate, hyaline, thin-walled. Pleurocystidia 35 – 66 (– 80) × 10 – 20 (– 25) µm, fusiform to fusoid-ventricose or narrowly lageniform, some with apical or completely enveloped in mucilage sometimes with adhering spores that obscure view, obtuse or capitate, hyaline, thin-walled. Pileipellis a transition from a euhymeniderm to a trichoderm over a subpellis, composed of a majority of terminal elements 40 – 69 × 8 – 12 µm, erect in clusters, especially at the disc, narrowly to broadly lageniform or narrowly fusoid, acute or subcapitate, arising directly from the subpellis or some with one to multiple basal cells, hyaline or with brown plasmatic pigment, non-incrusted, non-gelatinous, thin-walled; subpellis a cutis of repent hyphae, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 8 µm diam .. Pileus trama interwoven, composed of hyaline, non-incrusted, non-gelatinous, thin-walled, cylindrical to clavate hyphae, 3 – 22 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae, 3 – 12 µm diam .. Stipitipellis a cutis of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 8 µm diam .. Caulocystidia 22 – 74 × 8 – 16 µm, often clustered, fusiform to fusoid or lageniform, obtuse or acute, hyaline or with brown plasmatic pigment, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Gregarious on rotted wood in subtropical coastal mixed-use agro tree garden and secondary littoral broadleaf forest containing Annona muricata (Annonaceae), Artocarpus altilis (Moraceae), Barringtonia asiatica (Lecythidaceae), Cocos nucifera (Arecaceae), Cordia dichotoma (Boraginaceae), Euodia hortensis (Rutaceae), Leucaena leucocephala (Fabaceae), Macaranga dioica (Euphorbiaceae), and Musa sp. (Musaceae), Vanuatu (Tanna). Material examined: — VANUATU. Tafea Province: Tanna, Port Resolution. 19 ° 31.459 ′ S, 169 ° 30.340 ′ E, elev. 62 m, 14 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 281 (HAY). Notes: — The type variety, P. riberaltensis var. riberaltensis Singer (1958: 255), is only known from the original protologue based on Bolivian material (Singer, 1958). Based on this original description, the type variety differs from the Vanuatu material by having smaller cheilocystidia (33 – 44 × 11 – 16.5 µm), slightly wider pleurocystidia (41 – 86 × 12.5 – 39 µm) without mucilage, lacking caulocystidia, and having a cutis pileipellis consisting of cylindrical, rarely attenuate cells. In the same description, Singer proposed P. riberaltensis var. conquistensis Singer (1958: 255) from additional material he acknowledged differed based on the presence of black stripes on the stipe (Singer 1958). Recently, multiple Pluteus spp. type specimens were re-examined by Rodríguez (2024), including the type P. riberaltensis var. riberaltensis, which differs from this Vanuatu material by having Singer’s observed cutis type pileipellis, lacking the presence of mucilage on any cystidium, and lacking caulocystidia. A specimen of var. conquistensis was reported from Brazil (Menolli et al. 2010) differing based on having moderately longer pleurocystidia closer in size to the type variety. Based on phylogenetic analysis of ITS data (Fig. 37 d) the Vanuatu material diverges with strong support from the Brazilian specimen of P. riberaltensis var. conquistensis. Comparing the Vanuatu specimen to Singer (1958) and Menolli et al. ’ s (2010) material, P. riberaltensis var. conquistensis differs by having shorter and wider cheilocystidia ([27 –] 30 – 47 [– 57] × [12.5 –] 17.7 – 27 µm), slightly wider pleurocystidia ([44 –] 48 – 69 [– 78] × [15 –] 17.5 – 28 [– 35] µm) without mucilage, lacking caulocystidia, a pileipellis arranged as a cutis, and is phylogenetically distinct. The presence of dark fibrils on the stipe was considered exclusive to var. conquistensis, and as this occurs in the Vanuatu specimen, although inconsistently, the reliability of this character is questionable. Singer proposed another variety, P. riberaltensis var. missionensis Singer (1961: 123) from Argentina (Singer 1961) that he classified as having a white stipe like the type variety, but differing by the presence of incrustation on cystidia and lacking size differentiation between the pleurocystidia and cheilocystidia. Additional material of P. riberaltensis var. missionensis has also been reported from Mexico (Cifuentes & Guzmán 1981, Rodríguez 2013). Singer (1961) described the pleurocystidia and cheilocystidia together, regarding their sizes equal (41 – 69 × 12 – 22 µm), and by comparison both lamellar cystidia in the Vanuatu material are similarly shaped and roughly equal in length, but the cheilocystidia are slightly narrower. A brief description of Mexican material from the state of Chiapas also describes both the pleurocystidia and cheilocystidia together as equal (67.5 – 75 × 30 – 37.5 µm), and these differ from the Vanuatu specimen mainly by being slightly broader and mucilage was not observed (Cifuentes & Guzmán 1981). Rodríguez re-examined the Chiapas material and provided additional Mexican material from Veracruz and the state of Morelos, but only provided an illustration without a description (Fig. 10, Rodríguez 2013). Based on this, compared to the Vanuatu specimen the pileipellis terminal cells appear similarly shaped and arranged, and both lamellar cystidia types appear similarly shaped with both having a type of incrustation / mucilage. Apparently, Rodríguez also re-examined the type variety for comparison, but unfortunately did not provide additional information. Pileipellis terminal elements were not measured or detailed from any of the Mexican material, but Singer’s Argentinean specimen was reported as longer in size (45 – 160 × 13 – 26 µm) and described as “ appressed … the terminal members often combining to form bunches of ascending hyphae or pyramids which form the fibrils of the pileus ” (Singer 1961). Even navigating Singer’s key from that study requires classifying the pileipellis as a trichoderm to conclude at P. riberaltensis var. missionensis (Singer 1961). Based on this, Singer’s pileipellis description is slightly ambiguous and may be loosely interpreted as arranged similar to that in the Vanuatu material. Singer described the type var. riberaltensis as a cutis without specifying the ornamentation of the terminal elements, and var. conquistensis as “ … consisting of cylindric hyphae, the terminal members and the cylindric elements anteceding them fuscous and often ascendant, ” (Singer 1958). The Brazilian material of P. riberaltensis var. conquistensis characterized the pileipellis as a cutis “ … sometimes with the terminal elements slightly inflated and often ascendant, ” (Menolli et al. 2010). Assuming var. conquistensis and var. missionensis were established due to being closely analogous to the type variety, it may be their pileipellis is simply a cutis. The pileipellis arrangement in the Vanuatu material tends to have abundant, erect terminal elements, sometimes with one to multiple basal cells forming a chain, being the predominant feature of the surface and arising from a distinct cutis second layer, and here classified as a euhymeniderm-trichoderm. This contrasts with what this study interprets as a typical cutis arrangement, where the terminal elements may still be repent and integrate themselves into an overall parallel orientation, and sometimes ascending into erect clusters. The Vanuatu specimen is clearly closest to P. riberaltensis var. missionensis based on microscopic similarity with the other descriptions and the mucilaginous cystidia, which may be considered consistent a character for distinction. Singer’s consideration of equal pleurocystidia and cheilocystidia size as a defining feature of var. missionensis may be useful, but the overall defined size range for the variety is unclear as that of Mexican material is slightly larger compared to the Argentinean material, and within the Vanuatu material the cheilocystidia are typically slimmer than the pleurocystidia. The subtly fibrillose stipe, although sparse in some material, would make it closer to var. conquistensis, but this species is phylogenetically distinct and neither account mentions caulocystidia nor cystidia mucilage. Due to Singer’s ambiguous pileipellis classification for P. riberaltensis var. missionensis and vague descriptions from other material, this study prefers to maintain the Vanuatu specimen’s identity as P. aff. riberaltensis var. missionensis. An in-depth re-examination for morphological comparison and molecular sampling for all the varieties, especially the type, are necessary to clarify the relationships and delimitations among the varieties of P. riberaltensis. Phylogenetic analysis of ITS molecular data (Fig. 37 d) places the Vanuatu specimen within the general ephebeus clade sensu Menolli et al. (2015 b) with a well-supported sister taxon P. flavidus E. F. Malysheva & A. V. Alexandrova (2020: 96). This recently described Vietnamese species is close to the Vanuatu specimen, particularly in the very similar pileipellis arrangement with fusiform or needle-shaped terminal elements connected to basal cells (Malysheva et al. 2020). Pluteus flavidus was classified with a hymeniderm with transitions to an epithelium type pileipellis, which may subtly differ from P. aff. riberaltensis var. missionensis as it appears there are more pyriform or epithelioid cells compared to more elongate cells in the Vanuatu specimen. Even so, P. flavidus differs due to more sphaeropedunculate cheilocystidia, lacking mucilaginous pleurocystidia, irregularly shaped caulocystidia, and producing a paler pileus (Malysheva et al. 2020). The phylogenetically distantly related P. hirtellus Desjardin & B. A. Perry (2018: 612) from São Tomé is superficially similar, but differs by a paler shade of brown, lack of brown fibrils towards the stipe base, smaller more clavate non-capitate cheilocystidia (25 – 48 × 10 – 20 µm), more clavate non-mucilaginous pleurocystidia, longer pileipellis elements (48 – 115 × 8 – 16 µm), and lack of caulocystidia (Desjardin & Perry 2018). The Chinese P. squarrosus, shares similar pileipellis terminal elements, but these tend to be longer (50 – 120 × 7 – 13 µm) and the species differs in having non-mucilaginous pleurocystidia, shorter cheilocystidia (35 – 42 × 9 – 18 µm), and a more grayish brown pileus (Hosen et al. 2019).	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
03AC8791FFE25967FF7DF9601155FA10.taxon	materials_examined	Holotype: — VANUATU. Tafea Province: Futuna, upper slopes of Mount Tatafu. 19 ° 31.422 ′ S, 170 ° 13.433 ′ E, elev. 485 m, 19 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 304 (HAY). Etymology: — Named in honor of Mount Tatafu on Futuna Island, where the holotype specimen was collected, and the fact that the pileus surface resembles the furrowed flanks of Mount Tatafu. Diagnosis: — Pluteus tatafuensis from Futuna is characterized by a dark chocolate brown rugose-venose, fuliginous appressed-fibrillose, rimose, marginally sulcate pileus and a white stipe with fuliginous floccules towards the base. Microcharacters include subglobose basidiospores (6.4 × 5.8 µm), broadly clavate cheilocystidia, clavate pleurocystidia sometimes with mucilaginous coating, a transition between a hymeniderm and epithelium pileipellis consisting of globose and lageniform, frequently mucronate brown pigmented cells, fusoid capitate brown pigmented caulocystidia, and an absence of clamp connections. Description: — Pileus 28 mm diam., convex to hemispherical with a slight centrally depressed umbo, margin sulcate; surface dull, dry, appressed-fibrillose splitting radially in a rimose pattern exposing white context beneath, disc densely rugose-venose; veins dark chocolate brown to black, fibrils fuliginous to pallid brown (oac 730 – oac 732). Context 3 mm thick, white. Lamellae free, crowded with 3 + tiers of lamellulae, thin, dull pinkish brown. Stipe 35 × 3 mm, central, cylindrical over a straight base, hollow; surface dull, dry, silky, minutely flocculose at the base, white to off-white, floccules colored fuliginous to pallid brown, context white. Odor indistinct. Taste indistinct. Basidiospores (5 –) 6 – 7 × 5 – 7 µm µm [x m = 6.34 ± 0.55 × 5.84 ± 0.42 µm, Q = 1 – 1.2, Q m = 1.08 ± 0.08, n = 50, s = 1], globose to subglobose, smooth, hyaline, with a guttule, inamyloid, thick-walled. Basidia 23 – 30 × 9 – 10 μm, clavate, 4 - spored, hyaline, guttulate, thin-walled, sterigmata 2 – 4 × 0.5 – 1 μm. Basidioles 18 – 24 × 6 – 11 µm, clavate, hyaline, guttulate, thin-walled. Lamellar edge sterile. Cheilocystidia 30 – 118 × 11 – 70 µm, clavate to broadly clavate or sphaeropedunculate to inflated, obtuse, hyaline, thin-walled. Pleurocystidia 43 – 90 × 14 – 30 µm, clavate to broadly clavate, obtuse or seldom mucronate, some with apical or completely enveloped in mucilage sometimes with adhering spores that obstruct view, hyaline, thin-walled. Pileipellis a transition between a hymeniderm and epithelium to a euhymeniderm overlaying a subpellis; majority of terminal elements 35 – 85 × 6 – 56 µm, globose to broadly clavate or narrowly lageniform to filliform, obtuse, frequently mucronate or rostrate (up to 40 µm long), with brown plasmatic pigment or sometimes hyaline, non-incrusted, non-gelatinous, thin-walled; subpellis a cutis of repent hyphae, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 8 µm diam .. Pileus trama interwoven, composed of hyaline, non-incrusted, non-gelatinous, thin-walled, cylindrical hyphae, 3 – 20 µm diam .. Lamellar trama inverse, composed of hyaline, non-gelatinous, thin-walled hyphae 3 – 12 µm diam .. Stipitipellis a cutis, composed of hyaline, non-incrusted, non-gelatinous, thin-walled hyphae, 3 – 10 mm diam .. Caulocystidia 35 – 110 × 5 – 25 µm, common, solitary to clustered, clavate to cylindro-clavate or narrowly fusoid, some strangulate, infrequently forming trichoderm-like chains, obtuse or capitate, hyaline or pale brown plasmatic pigment, thin-walled. Clamp connections absent in all tissues examined. Habitat and known distribution: — Solitary on rotted wood in subtropical montane primary cloud broadleaf rainforest containing Atractocarpus sezitat (Rubiaceae), Claoxylon psilogyne (Euphorbiaceae), Eumachia trichostoma (Rubiaceae), Geissois denhamii (Cunoniaceae), Ficus septica (Moraceae), Neonauclea forsteri (Rubiaceae), and Schefflera neoebudica (Araliaceae), Vanuatu (Futuna). Material examined: — VANUATU. Tafea Province: Futuna, upper slopes of Mount Tatafu. 19 ° 31.422 ′ S, 170 ° 13.433 ′ E, elev. 485 m, 19 August 2019, coll. J. A. del Rosario & B. A. Perry, JAD 304, (HAY). Notes: — The combination of the rugose-venulose, rimose, marginally sulcate, and fuliginous pileus of P. tatafuensis suggests comparison to a number of similar looking species. The Bolivian P. substigmaticus Singer (1958: 273) produces very similar basidiomes, shares a similarly shaped pileipellis, pleurocystidia and cheilocystidia cells, but differs by the pileus lacking a venose disc and has significantly smaller cheilocystidia and pleurocystidia (15.5 – 42 × 10.3 – 16.5 µm equally), which lack mucilage (Singer 1958). Pluteus rimosoaffinis Singer (1956: 211), an Argentinean (Singer 1956) and confirmed Brazilian species (Pegler 1997, de Meijer 2006; Menolli & Capelari, 2016), has similarly sized and shaped pleurocystidia with apical mucilage, but this species tends to be larger in stature, is not known to have caulocystidia, lacks mucronate or filiform pileipellis elements, and has more utriform non-sphaeropedunculate cheilocystidia. Other similar dark venose species include the tropical American P. jamaicensis Murrill (1911: 278) (Dennis 1953, Menolli & Capelari 2010, Murrill 1911, Pegler 1983 a, Singer 1956, 1958, Singer & Digilio 1952), P. fluminensis Singer (1958: 292) from Brazil, Bolivia and the U. S. A. (Singer 1958, Menolli et al. 2010), and the Chilean P. fuligineovenosus Horak (1964: 190) (Horak 1964), but these all differ due to more lageniform non-mucilaginous pleurocystidia, non-sphaeropedunculate cheilocystidia, lack of rostrate and lageniform pileipellis elements, and are phylogenetically distinct. Phylogenetic analysis of ITS data (Fig. 37 e) places P. tatafuensis within the romelli / aurantiorugosus clade recognized by Justo et al. (2011 b), and sister to an undetermined species of Pluteus from China (KU 382737, KU 382736) with strong support (BS 97 %, PP 0.99). These taxa are placed on a well-supported branch containing additional superficially similar species P. paucicystidiatus Menolli, Justo & Capellari (2015: 1218), P. stenotrichus Justo, Battistin & Angelini (2012: 17), P. castaneorugosus E. F. Malysheva & A. V. Alexandrova (2020: 461), P. iguazuensis Singer (1956: 201), and an unidentified Pluteus sp. from the Dominican Republic (KM 983705). Compared to P. tatafuensis the Brazilian P. paucicystidiatus shares similarly shaped cheilocystidia and pileipellis elements, but these are smaller and the species differs by not having (or only sometimes) pleurocystidia, differently shaped shorter caulocystidia, and a paler brown pileus (Menolli et al. 2015 b). From the Dominican Republic, P. stenotrichus differs in producing a paler brown non-sulcate pileus, smaller cheilocystidia (25 – 50 × 14 – 20 µm), pleurocystidia lacking mucilage, differently shaped non-mucronate pileipellis elements, and similarly shaped but shorter caulocystidia (31 – 63 × 12 – 24 µm) (Justo et al. 2012). Pluteus castaneorugosus from Vietnam differs in having smaller spores (5 – 6 × 4.5 – 5.5 µm), smaller non-mucilagenous pleurocystidia (35 – 55 × 15 – 22 µm), smaller thick-walled cheilocystidia (25 – 43 × 14 – 20 µm), and a differently shaped non-mucronate pileipellis (Malysheva et al. 2020). Finally, P. iguazuensis from Argentina (Singer 1958) and Brazil (Menolli & Capelari 2016) differs in having a non-rugose, non-rimose pileus, shorter cheilocystidia, non-mucilaginous pleurocystidia, lack of caulocystidia, and lack of lageniform or mucronate elements in the pileipellis.	en	Del, Jonathan A., Perry, Brian A. (2025): The genus Pluteus (Basidiomycota, Agaricales, Pluteaceae) from Tafea Province, Republic of Vanuatu. Phytotaxa 709 (1): 1-104, DOI: 10.11646/phytotaxa.709.1.1, URL: https://doi.org/10.11646/phytotaxa.709.1.1
