Subulicystidium acerosum S.H. He & S.L. Liu

Liu, Shi-Liang, Ma, Hai-Xia, He, Shuang-Hui & Dai, Yu-Cheng, 2019, Four new corticioid species in Trechisporales (Basidiomycota) from East Asia and notes on phylogeny of the order, MycoKeys 48, pp. 97-113 : 103-104

Subulicystidium acerosum S.H. He & S.L. Liu sp. nov. Fig. 4

Typification.

CHINA. Guizhou Province, Libo County, Maolan Nature Reserve, on fallen angiosperm trunk, 16 Jun 2016, He 3804 (holotype, BJFC 022303).

Etymology.

“acerosum” refers to the presence of numerous needle-like crystals.

Basidiomata.

Annual, resupinate, effused, very thin, easily separated from the substrate, up to 6 cm long, 2 cm wide. Hymenophore surface smooth, more or less arachnoid, white (5A1) to orange grey (5B2); margin undifferentiated.

Microscopic structures.

Hyphal system monomitic; generative hyphae with clamp connections, hyaline, thin-walled, frequently branched and septate, loosely interwoven, 2-3.5 µm in diam. Cystidia abundant, subulate, projecting beyond hymenium, hyaline, thick-walled and regularly covered with rectangular crystals at basal part, thin-walled and smooth at apex part, 50-100 × 3-5 µm. Crystals numerous, distributed in whole section or more commonly attached on cystidia, acerose, hyaline. Basidia short clavate, hyaline, thin-walled, with 4 sterigmata and a basal clamp connection, 15-20 × 4-5.5 µm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores narrowly fusiform to slightly vermicular, hyaline, thin-walled, smooth, negative in Melzer’s reagent, acyanophilous, (14.5 –)15.5–18(– 20) × 1.8-2.2 µm, L = 16.6 µm, W = 2 µm, Q = 8.3 (n = 30/1).

Remarks.

Subulicystidium acerosum is characterised by the long and narrow basidiospores and presence of numerous acerose crystals. The species is similar to S. longisporum (Pat.) Parmasto, which differs in having slightly shorter and wider basidiospores (12-16 × 2-3 µm, Q <7, Ordynets et al. 2018). Subulicystidium cochleum Punugu is similar to S. acerosum by sharing needle-like crystals but differs in having larger basidiospores (20-27 × 2-3 µm, Punugu et al. 1980; Ordynets et al. 2018). Phylogenetically, S. acerosum is distinct from all the other sampled species of Subulicystidium (Fig. 2).