Trechispora gracilis S.L. Liu & L.W. Zhou
MycoBank number: MB 559891; Index Fungorum number: IF 559891; Facesoffungi number: FoF 12870
Basidiomes annual, resupinate, effused, thin, soft, easily separated from substrates, up to 10 cm long, 2 cm wide, 50 µm thick. Hymenophore smooth, arachnoid, cream to light ash-grey when fresh, ash-grey when dry, not cracked. Margin white, thinning out as byssoid, 0.5 mm wide. Hyphal system monomitic; generative hyphae with clamp connections. Subicular hyphae long-celled, hyaline, slightly thick-walled, frequently branched and septate, interwoven, 2.5–3.5 µm in diam, ampullate septa up to 5 μm wide. Subhymenium composed of indistinct generative hyphae, much branched. Cystidia absent. Crystals absent. Basidia cylindrical with a slight median constriction, hyaline, thin-walled, with four sterigmata and a basal clamp connection, 10–13 × 4–5 µm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores ellipsoid, hyaline, thin-walled, aculeate, inamyloid, indextrinoid, acyanophilous, (2.5–)2.8–3.2 × (2–)2.3–2.8(–2.9) µm, L = 3.0 µm, W = 2.5 µm, Q = 1.2 (n = 60/2).
Material examined: CHINA, Jiangxi, Jiujiang, Bailudong Academy, on fallen gymnosperm branch, 26 June 2021, L.W. Zhou, LWZ 20210626-5b (holotype in HMAS).
Notes: Trechispora gracilis resembles T. damansaraensis by thin basidiomes and smooth hymenophore; however, T. damansaraensis differs in cream, straw-yellow to cinnamon-buff hymenophore, the occasional presence of crystals in subiculum and slightly longer basidiospores (3–3.8 µm in length).
Fig. 1. Basidiomes of Trechispora gracilis (LWZ 20210626-5b, holotype). — Scale bars: a = 1 cm; b = 1 mm.
Fig. 2. Microscopic structures of Trechispora gracilis (drawn from the holotype). a. Vertical section of basidiomes; b. Basidia; c. Basidiospores. — Scale bar = 10 μm.