Lyomyces niveus C.L. Zhao ex L.W. Zhou & Xue W. Wang, sp. nov.
Index Fungorum number: IF 900293; Mycobank number: MB 900293; Facesoffungi number: FoF 14056.
Based on Lyomyces niveus C.L. Zhao, in Luo, Chen & Zhao, Nordic Jl Bot.(e03414): 7 (2021), invalid name, not effectively published.
Holotype – CLZhao 6496 (SWFC).
Basidiomes annual, resupinate, subcoriaceous when fresh, becoming pruinose upon drying, up to 20 cm long and 3.5 cm wide, 50–130 μm thick. Hymenial surface smooth, white when fresh, turning white to pale buff upon drying. Margin indistinct, white.
Hyphal system monomitic; generative hyphae with clamp connections, colorless, thin-walled, frequently branched; subhymenium with moderately encrusted crystals, 1.5–4.0 μm in diameter; IKI–, CB–; tissues unchanged in KOH.
Cystidia of two types – 1) capitate cystidia colorless, thin-walled, smooth, 12.5–20.5×4.5–5.0 μm; 2) fusiform cystidia colorless, thin-walled, smooth, 12.5–22.0×3.0–5.0 μm; cystidioles absent. Basidia barreled, with 4 sterigmata and a basal clamp connection, 9.5–15.0×3.5–5.5 μm; basidioles abundant, in shape similar to basidia, but slightly smaller.
Basidiospores broadly ellipsoid, colorless, thin-walled, smooth, IKI–, cyanophilous, with a single oil-like globule, (3.0–)3.5–5.0(–6.5)×(2.5–)3.0–4.0(–5.0) μm, L=4.45 μm, W=3.31 μm, Q=1.28–1.46 (n=150/5).
Material examined – China, Yunnan Province, Yuxi, Xinping County, Mopanshan National Forestry Park, 101°57′E, 23°57′N, 2185 m a.s.l., on the trunk of Pinus armandii, leg. 19 January 2018, C.L. Zhao, CLZhao 6496 (SWFC, holotype).
GenBank numbers – CLZhao 6496: ITS = MZ262545, LSU=MZ262530.
Notes – Lyomyces niveus was published with a detailed description and phylogenetic analyses inferred from combined ITS and nLSU regions (Luo et al. 2021). However, it was indicated that the holotype (CLZhao 6496) was deposited at two separated herbaria (SWFC and HKAS, Luo et al. 2021), which is contrary to Art. 40.7 of the International Code of Nomenclature for algae, fungi, and plants (Turland et al. 2018). The current phylogeny (Fig. 1) confirms the phylogenetic conclusion of Luo et al. (2021), and thus we validate L. niveus here by reproducing the original description and selecting the piece of CLZhao 6496 at SWFC as the holotype. Then, the other piece of CLZhao 6496 at HKAS should be the isotype.
Figure 1 – Phylogram generated by the maximum likelihood algorithm based on combined nLSU and ITS sequence data is presented along with the bootstrap values and the Bayesian posterior probabilities above 50% and 0.8, respectively, at the nodes. Type specimens are in bold and the isolates of new species characterized are in blue