Protohydnum sp.

Spirin, Viacheslav, Malysheva, Vera, Viner, Ilya, Alvarenga, Renato Lúcio Mendes, Grebenc, Tine, Gruhn, Gérald, Savchenko, Anton, Grootmyers, Django, Ryvarden, Leif, Vlasák, Josef, Larsson, Karl-Henrik & Nilsson, R. Henrik, 2025, Additions to the taxonomy of the Auriculariales (Basidiomycota) with pedunculate basidia, MycoKeys 120, pp. 339-392 : 339-392

Protohydnum sp. Vlasák 1808/145

Description.

Basidiocarps effused, up to 4 cm in widest dimension, smooth, cartilagineous, opaque, cream-coloured, with pinkish or brownish stains, 0.5–1 mm thick, in dry condition greyish, often with ochraceous or brownish spots, crust-like, margin sharply delimited, adnate or partly detaching. Hyphal structure monomitic, hyphae hyaline, clamped, thin- or slightly thick-walled, homogeneous throughout, tightly interwoven, and strongly glued together, 1.5–2.5 μm in diam. Cystidia absent. Probasidia clavate, embedded, 12–15 × 6–7 μm. Mature basidia and basidiospores not observed.

Remarks.

In our phylogenetic analyses, this unnamed taxon appears as a sister species of P. cartilagineum and P. ocellatum (Figs 1 , 2 ). However, the single studied specimen collected in French Guiana is sterile, and we therefore leave it without a formal description.

Figures

Figure 1. Bayesian majority-rule consensus ITS + LSU-based tree of the Auriculariales overlaid with bootstrap support values from the maximum likelihood analysis. Support values are given as Bayesian posterior probabilities / ML bootstrap percentages. Species with stalked basidia are marked with a red X. I – Protohydnum clade; II – Elmerina clade; III – Hydrophana clade; IV – Endoperplexa – Mycostilla clade; V – Protoacia – Gelacantha clade; VI – Protomerulius clade; VII – Myxarium clade. The Sebacinales (Ditangium P. Karst., Sebacina, and Serendipita P. Roberts spp.) and Exidiopsis gloeophora were used as outgroups.

Figure 2. Bayesian majority-rule consensus ITS-based tree of the Protohydnum clade. Support values are given as Bayesian posterior probabilities. Basidiodendron spp. were used as an outgroup.