Trichocybe, a new genus for Clitocybe puberula (Agaricomycetes, Agaricales)

Trichocybe, a new genus of Agaricales, is described to accommodate the rare species Clitocybe puberula characterized by an isolated phylogenetic position. Trichocybe is distinguished from its allied clitocyboid genera by a unique combination of macro- and micromorphological characters, including a Gymnopus-like habitus, a pubescent pileus with squamulose flocci, an eccentric stipe growing on wood debris, a putrescent non-reviviscent context, a strongly farinaceous odour, rare but clearly-differentiated cheilocystidia, an unusual, strongly differentiated pileipellis, a subpellis with vesiculose-physaloid elements, a stipitipellis with diverticulate hyphae, and smooth, acyanophilous, inamyloid basidiospores. Trichocybe is so far known only from northwestern Europe. Based on a LSU- and 5.8S-rDNA Bayesian phylogenetic analysis, Trichocybe clusters within the Tricholomatoid clade, where it occupies an isolate position. Furthermore, according to the present analysis, also Clitocybe phaeophthalma seems to represent an independent evolutive line in the clitocyboid fungi, which suggests adopting the genus Singerocybe Harmaja for this taxon as well as similar ones.