Hymenochaetales » Schizoporaceae » Xylodon

Xylodon asiaticus

Xylodon asiaticus X.C. Zhang & C.L. Zhao,

MycoBank number: MB 850228.

Basidiomata Annual, resupinate, adnate, coriaceous, very hard to separate from substrate, without odor or taste when fresh, up to 15 cm long, 2 cm wide, less than 1 mm thick. Hymenial surface hydnoid, aculei 4–6 per mm, up to 0.5 mm long, buff when fresh, turning to buff to ochraceous upon drying. Sterile margin distinct, slightly buff, up to 1 mm wide. Hyphal structure Hyphal system monomitic, generative hyphae with clamp connections, colorless, thin-walled, branched, interwoven, 2–3.5 μm in diameter; IKI–, CB–, tissues unchanged in KOH. Hymenium Cystidia and cystidioles absent. Basidia barrelled to subcylindrical, with 4 sterigmata and a basal clamp connection, 11.5–20 × 4–5 μm; basidioles dominant, similar to basidia in shape, but slightly smaller. Basidiospores: Ellipsoid to subcylindrical, colorless, smooth, thin-walled, with 1–2 oil drops, IKI–, CB–, (3.7)4–5.2(–6) × (2.5–)2.8–3.5(–4) μm, L = 4.72 μm, W = 2.97 μm, Q = 1.59–1.91 (n = 120/4). Type of rot White rot.

Additional specimens examined: CHINA. Yunnan Province, Yuxi, Xinping County, Mopanshan National Forestry Park, 23°55′48′′N, 101°59′22′′E, elev. 2150 m, on the trunk of Quercus semecarpifolia, 19 August 2017, leg. C.L. Zhao, CLZhao 2282 (SWFC!), GenBank No. (ITS OM959481; nLSU OM967416); Dali, Nanjian County, Lingbaoshan National Forest Park, 24°46′58′′N, 100°30′46′′E, elev. 2522 m, on fallen angiosperm branch, 10 January 2019, leg. C.L. Zhao, CLZhao 10430 (SWFC!), Wenshan, Xichou County, Pingzhai Forestry Farm, 23°26′27′′N, 104°40′48′′E, elev. 1500 m, on fallen angiosperm branch, 18 January 2019, leg. C.L. Zhao, CLZhao 11531 (SWFC!), GenBank No. (ITS OM959471).

Notes: Morphologically, Xylodon asiaticus resembles X. asper (Fr.) Hjortstam & Ryvarden. (2009: 34), X. australis (Berk.) Hjortstam & Ryvarden. (2007: 98) and X. tenuicystidius (Hjortstam & Ryvarden) Hjortstam & Ryvarden. (2009: 41) in having ellipsoid or cylindrical basidiospores. However, X. asper can be delimited from X. asiaticus by its odontioid hymenial surface and longer basidia (20–25 × 4–5 μm, Hjortstam & Ryvarden 2009); X. australis is distinguished from X. asiaticus by its grandinoid hymenial surface and larger basidiospores (6–7.5 × 4–4.5 μm, Hjortstam & Ryvarden 2007); X. tenuicystidius differs from X. asiaticus by its tuberculate hymenial surface and longer basidia (20–25 × 3–4 μm, Hjortstam & Ryvarden 2009).

Fig. 1 Maximum Parsimony strict consensus tree illustrating the phylogeny of the new species Xylodon asiaticus and related species in Xylodon based on ITS sequences. Branches are labeled with Maximum Likelihood bootstrap values equal to or above 70%, Maximum Parsimony bootstrap values equal to or above 50% and Bayesian posterior probabilities equal to or above 0.95.