Trechispora tuberculata S.L. Liu & L.W. Zhou, sp. nov.

Index Fungorum number: IF 901063; Mycobank number: MB 901063; Facesoffungi number: FoF 14816; Figs. 1, 2, 3

Etymology – tuberculata (Lat.) referring to tubercules on spines of basidiospores.

Holotype – BJFC024964.

Diagnosis – Differing from other species of Trechispora by having numerous tubercules on spines of basidiospores.

Basidiomes annual, resupinate, effused, thin, soft, easily separated from substrates, up to 4 cm long, 3 cm wide. Hymenophore hydnoid with numerous, small aculei, strawyellow to bluish grey when dry. Margin undifferentiated.

Hyphal system monomitic; generative hyphae with clamp connections. Subicular hyphae hyaline, thick-walled, moderately branched and septate, subparallel, 3–5 µm in diam. Tramal hyphae distinct, hyaline, thin or thick-walled, moderately branched, smooth, subparallel, 2–3.5 μm in diam. Cystidia absent. Crystals usually present, bipyramidic, aggregated. Basidia cylindrical with a slight median constriction, hyaline, thin-walled, with 4 sterigmata and a basal clamp connection, 15–20×5–6 µm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores abundant, ellipsoid, hyaline, thin to slightly thick-walled, aculeate, with numerous tubercules on spines, IKI–, CB–, (3–)3.3–4(–4.3)×2.7–3.2 µm, L=3.7 µm, W=3 µm, Q=1.2 (n=30/1).

Material examined – Brazil, Pernambuco State, Recife, Recife Botanical Garden, on fallen angiosperm trunk, 16 May 2017, Yu-Cheng Dai, Dai 17433 (BJFC024964, holotype; isotype in HMAS).

GenBank numbers – ITS=OM523507, LSU=OM339314.

Notes – Trechispora tuberculata resembles T. constricta by hydnoid hymenophore; however, T. constricta differs in the presence of thick-walled generative hyphae and aculeate basidiospores with a slight constriction in the middle-upper part of spines (Liu et al. 2022b).

Figure 1 – Basidiomes of Trechispora tuberculata (Dai 17433, holotype). Scale bars: a=1 cm, b=1 mm

Figure 2 – Microscopic structures of Trechispora tuberculata (Dai 17433, holotype). a A vertical section of basidiomes. b Basidia. c Basidiospores. Scale bars: 10 μm

Figure 3 – Scanning electron micrograph of basidiospores of Trechispora tuberculata (Dai 17433, holotype). Scale bars: 2 μm