Trechispora alba S.L. Liu, G. He & L.W. Zhou, sp. nov.

Index Fungorum number: IF 901060; Mycobank number: MB 901060; Facesoffungi number: FoF 14813; Figs. 1, 2, 3

Etymology – alba (Lat.) referring to the white colour of basidiomes.

Holotype – HG 19350 (HMAS).

Diagnosis – Differing from Trechispora pallescens in slightly wider basidiospores (de Meiras-Ottoni et al. 2021).

Basidiomes annual, clavarioid, solitary or in small groups, densely branched, moderately open, fleshy consistency, white when fresh, cream to curry-yellow when dry, 2–8 cm high. Branches polychotomous, axils V-shaped, somewhat palmately branched, slightly flattened, 2–5 mm wide, occasionally flattened to 10 mm, tips subacute to blunt. Stipe white to cream, 5–15×2–3 mm.

Hyphal system monomitic; generative hyphae with clamp connections. Subicular hyphae hyaline, thick-walled, cylindrical, moderately branched and septate, subparallel, 2–3.5 μm in diam; ampullate septa usually present in the hyphae at the base of the stipe, up to 6–7 μm wide. Subhymenial hyphae short-celled and wide, 2–3.5 µm in diam, much branched. Basidia suburniform to subclavate, hyaline, thin-walled, with four sterigmata and a basal clamp connection, agglutinated, 20–26 × 5–8 µm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores ellipsoid, hyaline, thin-walled, aculeate, IKI–, CB–, 5–7(–7.5)×(3.3–)3.5–5(–5.5) µm, L=5.7 µm, W=4.1 µm, Q=1.4 (n=60/2).

Material examined – China, Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, Mengla County, on ground, 30 July 2019, G. He and Y. Chen, HG 19350 (HMAS, holotype); Yunnan Province, Honghe Hani and Yi Autonomous Prefecture, Honghe County, Dayangjie Township, on ground, 22 August 2021, J.W. Guo, CH 21384 (HMAS).

GenBank numbers – HG 19350: ITS= OM523516; CH 21384: ITS=OR557258.

Notes – Trechispora alba is similar to T. caulocystidiatus and T. gelatinosa by white to yellowish white basidiomes when fresh and the presence of cystidial structures. However, T. caulocystidiatus differs from T. alba in the presence of reddish-brown apices on basidiomes, caulocystidial hairs in stipitipellis and smaller basidiospores (3.5–4.5×3–3.5 µm, Furtado et al. 2021); T. gelatinosa differs in its dull yellow to brownish orange basidiomes when dried and smaller basidiospores (3.2–4.5×2.5–3.5 µm, de Meiras-Ottoni et al. 2021).

Figure 1 – Basidiomes of Trechispora alba (HG 19350, holotype). Scale bars: a=1 cm, b=1 mm

Figure 2 – Microscopic structures of Trechispora alba (HG 19350, holotype). a A vertical section of basidiomes. b Hyphae from subiculum. c Basidia. d Cystidia. e Basidiospores. Scale bars: 10 μm

Figure 3 – Scanning electron micrograph of basidiospores of Trechispora alba (HG 19350, holotype). Scale bars: 2 μm