Lyomyces niveomarginatus Q. Yuan & C. L. Zhao 2024, sp. nov.

Lyomyces niveomarginatus Q. Yuan & C. L. Zhao sp. nov. Figs 5, 6 Type material. Holotype. China • Yunnan Province, Wenshan, Wenshan National Nature Reserve, GPS coordinates 23°21'N, 104°10'E, altitude 1950 m, on a fallen branch of angiosperm, leg. C. L. Zhao, 26 July 2019, CLZhao 16360 (SWFC). Etymology. Niveomarginatus (Lat.) refers to the niveous margin of basidiomata. Description. Basidiomata annual, resupinate, adnate, subceraceous, without odour and taste when fresh and up to 7.5 cm long, 2 cm wide, 150 µm thick. Hymenial surface crackled, white to cream when fresh, to cream to slightly buff upon drying. Sterile margin distinct, whitish and up to 2 mm wide. Hyphal system monomitic, generative hyphae with clamp connections, colourless, thin-walled, branched, 1.5–3.5 µm in diameter; IKI –, CB –, tissues unchanged in KOH. Numerous crystals present amongst generative hyphae. Cystidia of two types: (1) fusoid, colourless, thin-walled, smooth, 25–29 × 2–3 µm; (2) clavate, colourless, thin-walled, smooth, 20–25.5 × 4.5–5.5 µm; basidia subclavate, with 4 sterigmata and a basal clamp connection, 23–29 × 2.5–3.5 µm. Basidiospores ellipsoid, colourless, thin-walled, smooth, with one oil drop, CB –, IKI –, 4.5–7 × (2.5 –) 3–4 µm, L = 5.51 µm, W = 3.15 µm, Q = 1.75 (n = 30 / 1). Additional specimens examined (paratypes). China • Yunnan Province, Wenshan, Wenshan National Nature Reserve, GPS coordinates 23°21'N, 104°10'E, altitude 1950 m, on a fallen branch of angiosperm, leg. C. L. Zhao, 7 August 2024, CLZhao 40333, CLZhao 40334 (SWFC).