Inocybe hamadryadis Rodr.-Campo, Bandini & Olariaga, 2023

Rodríguez-Campo, Francisco J., Bandini, Ditte & Olariaga, Ibai, 2023, Inocybe hamadryadis (Inocybaceae, Agaricales), a new smooth-spored species from Europe and West Asia, Phytotaxa 594 (3), pp. 191-203 : 196-198

Inocybe hamadryadis Rodr.-Campo, Bandini & Olariaga sp. nov.

( Figs. 2–3 )

MycoBank MB 845574

Etymology:—In Greek mythology “hamadryádes” is a nymph linked to a type of trees.

Diagnosis —Small to medium basidiomata with a non-hygrophanous pileus, brown to dark-brown colour, and at most innately fibrillose pileus surface, when young sometimes faintly covered by a whitish-greyish velipellis. The stipe has no pinkish tinge and is pruinose directly below the lamellae. The basidiospores are smooth, median in size, no papillate and pleurocystidia sometimes subcapitate. It grows mainly associated with Quercus . By those combined characteristics as well as by ITS sequences data, it differs from the morphologically and genetically closely related species I. tenuicystidiata .

Holotype:— SPAIN. Comunidad de Madrid: Hoyo de Manzanares, elev.: 969 m, coord. 40.611658 / -3.909139, 14 December 2021, in humus of Quercus ilex L. (1753b: 995) and Juniperus oxycedrus L. (1753b: 1038) on acidic soil, J.A. Rodea-Butragueño, A. Díaz-Fernández and F.J. Rodríguez-Campo (holotype MA-Fungi 98476 ! ; isotypes priv. herb. F.J. Rodríguez-Campo PRC-201214-02 , priv. herb. D. Bandini DB14-12-20-2 -Rodr.-Campo). GenBank acc. no: OP480841 .

Description:—Pileus 25–50 mm wide, at first (sub)conical to (sub)campanulate, later plano-convex to expanded, usually with a rather low large umbo; margin at first deflexed or slightly inflexed, later straight or even uplifted and then depressed around the centre; young basidiomata sometimes faintly covered in part by a whitish-greyish velipellis at the center of the pileus; pale brown to brown in different nuances, also chestnut brown up to dark chocolate or umber brown (Mu 7.5YR 5/4–5/6, 4/4–4/6, 3/4 to 10YR 4/4–4/6, 3/4–3/6; 5YR 3/3–3/4), sometimes almost blackish brown at the centre; surface generally smooth to minutely tomentose, sometimes minutely innately fibrillose, at the centre sometimes slightly subsquamulose, and occasionally subrimulose at the margin; young basidiomata with traces of a cortina. Lamellae moderately crowded to crowded (L = 40–80, l = 1–3), emarginate or adnate, at first whitish or greyish-whitish, then brown to intensely rusty brown, sometimes with a faint olivaceous reflection; edge crenulate, fimbriate, whitish to concolorous with the sides. Stipe 20–45 × 3–8 mm, cylindrical or curved, sometimes slightly thickening towards the base or with a subbulbous base; at first covered with a whitish, sometimes floccose tomentum, later longitudinally striate or glabrous when touched or with age; greyish-brownish colour in different nuances; pruinose at the extreme apex of the stipe. Context fibrose, whitish in pileus and stipe or with a grey-cream hue in the pileus. Odour spermatic. Taste fungoid or subspermatic. Exsiccata no darkening or blackening on drying.

Basidiospores 6.9–10.4 (av. 8.5 µm, SD 0.7 µm) × 4.4–5.8 (av. 5.2 µm, SD 0.3 µm). Q = 1.4–2.0 (av. 1.7, SD 0.1) (n = 120 from 3 coll.), (sub)amygdaloid, generally without suprahilar depression, apex (sub)conical, sometimes also subpapillate, sometimes with a thinning of the spore wall near the apex. Basidia 23–29 × 7–9 µm (n = 15); usually 4- spored, sometimes 2-spored, and then spores up to 11.2 µm. Pleurocystidia 44–80 µm (av. 60 µm, SD 8 µm) × 8–16 µm (av. 12 µm, SD 2 µm) (n = 45 from 3 coll.), numerous, (sub)fusiform, (sub)utriform, sometimes also sublageniform, with short or longer neck often with more or less sinuous walls, at the apex wide, usually with a short pedicel, seldom without pedicel, sometimes with (sub)capitate apex, generally crystalliferous at the apex, walls up to 1.9 µm thick at the apex, yellowish-greenish with 5% KOH. Cheilocystidia 37–70 µm (av. 53 µm, SD 9 µm) × 8–15 µm (av. 11 µm, SD 1 µm) (n = 45 from 3 coll.), similar in shape and occasionally with a brown or yellow-brown granular content; numerous clavate or (sub)pyriform paracystidia 16–28 µm (av. 21 µm, SD 3 µm) × 6–16 µm (av. 9 µm, SD 2 µm) (n = 45 from 3 coll.), some of them articulated at the base. Caulocystidia at the extreme apex of the stipe, 44–72 (av. 57 µm, SD 8 µm) × 8–14 µm (av. 11 µm, SD 2 µm), (sub)fusiform, (sub)cylindrical, with sinuous necks, walls usually somewhat thinner than of hymenial cystidia, up to 0.5 µm thick at the apex, sometimes crystalliferous, intermixed with (sub)clavate cauloparacystidia. Pileipellis a cutis formed by parallel cylindrical cells, 4–9 µm wide, sometimes with extracellular dark-brown incrustations. Clamp connections present in all tissues.

Habitat: — Scattered or gregarious in a Mediterranean forest on acid soil, in which Quercus ilex subsp. ballota is the main tree, accompanied by Fraxinus angustifolia L. (1753b: 1057), Juniperus oxycedrus L. (1753b: 1038), and Quercus faginea Lam. (1785: 725) . The underlying scrub is formed by a mixed shrubs of Cistus ladanifer L. (1753: 523), Salvia rosmarinus Spenn. (1835: 447) and Lavandula sp.

Phenology: — The dry-continental weather is the main climate, with hot summer, (average in summer: 25.6 ºC) and cold-dry winter, (average in winter 5.5 º C), with a non-prolonged rainy period. At the moment all collections have been found in late autumn and winter.

Distribution: — The species is up to now only known from our own collections from Spain as well as from Sweden from a sequence in GenBank (as “ Inocybe spec. ”, AM882987). In addition, there are several EcM-sequences in GenBank and/or UNITE from France (HQ204676, with Quercus ilex ), Germany (KM576441, with Quercus petraea (Matt.) Liebl. (1784: 403)) , Iran (UDB017527, FR852267), Italy (HF565068 and GU256196, the latter with Quercus suber L. (1753b: 995)). So, it seems that the species is widespread and associated with Quercus .

Additional collections examined: — SPAIN. Comunidad de Madrid: Villa del Prado, elev. 480 m, coord. 40.254673 / -4.283328, 26 December 2012, in humus of Quercus ilex on acidic soil, A. Díaz Fernández, J.A. Rodea Butragueño, Noemí Núñez Mauriz and F.J. Rodríguez Campo (MA-Fungi 98704!, duplicate in priv. herb. PRC-121226-13). GenBank acc. no.: OP480836; Ibidem, 26 December 2012, A. Díaz Fernández, J.A. Rodea Butragueño, Noemí Núñez Mauriz and F.J. Rodríguez Campo (MA-Fungi 98705!, duplicate in priv. herb. PRC-121226-15). GenBank acc. no.: OP480835; Ibidem 26 December 2012, A. Díaz Fernández, J.A. Rodea Butragueño, Noemí Núñez Mauriz and F.J. Rodríguez Campo (MA-Fungi 98706!, duplicate in priv. herb. PRC-121226-16). GenBank acc. no.: OP480834; Ibidem, 26 December 2012, A. Díaz Fernández, J.A. Rodea Butragueño, Noemí Núñez Mauriz and F.J. Rodríguez Campo (MA-Fungi 98707!, duplicate in priv. herb. PRC-121226-25). GenBank acc. no.: OP480840; Ibidem 3 March 2014, A. Díaz Fernández, J.A. Rodea Butragueño and F.J. Rodríguez Campo (MA-Fungi 98650!, duplicate in priv. herb. PRC-140303-05). GenBank acc. no.: OP480837; Ibidem 6 March 2017, J.A. Rodea Butragueño, A. Díaz Fernandez and F.J. Rodríguez Campo (MA-Fungi 98651!, duplicate in priv. herb. PRC-170306-01). GenBank acc. no.: OP480838; Comunidad de Madrid: Rascafría, elev.: 112 m, coord. 40.898330 / -3.861319, 13 October 2021, in humus of Quercus pyrenaica Willd. (1805: 451) and Prunus spinosa L. (1753: 475) on acidic soil, A. Díaz Fernández, J.A. Rodea Butragueño and F.J. Rodríguez Campo (MA-Fungi 98708! duplicate in priv. herb. PRC 211013-01). GenBank acc. no.: OP480839.

Figures

FIGURE 2. Inocybe hamadryadis: a: MA-Fungi 98476 (holotype) fresh basidiomata b: MA- Fungi 98651 fresh basidomata c: Basidiospores; d: Pleurocystidia; e: Cheilocystidia; f: Caulocystidia. (All microphotos from MA-Fungi 98476, holotype—Scale bars: a–b: 1 cm. Photos by F.J. Rodríguez-Campo.

FIGURE 3. Inocybe hamadryadis MA-Fungi 98476 (holotype): microscopic structures (Ca: Caulocystidia, Ch: Cheilocystidia, Cpa: Cauloparacystidia, Pa: Paracystidia, Pl: Pleurocystidia, sp: Basidiospores). Drawings by D. Bandini