Pseudoclitocybaceae fam. nov. (Agaricales, Tricholomatineae), a new arrangement at family, genus and species level

A new classification of several clitocyboid taxa is here proposed to accommodate results from multigenic phylogenetic inference. The analysis of ITS rDNA as well as a combined dataset including 18S and 28S rDNA, tef1 and rpb2 data, support significantly a shared monophyletic origin of the genera Pseudoclitocybe, Musumecia and Pogonoloma, and the species Clitocybe alexandri and C. harperi. The new family Pseudoclitocybaceae is here proposed to name this clade, characterized by the presence of loop-like clamp connections in most species, absence of cystidia, and parallel hymenophoral trama with broad, cylindrical hyphae with intracellular granulations. The new genera Clitopaxillus and Harmajaea are proposed to accommodate the type species C. alexandri and H. harperi, as well as the combination H. wellsiae. In addition, two new species are described: C. fibulatus has a differential distribution of clamp connections in the basidiome, while H. guldeniae is, by now, an exclusively European taxon with brownish pileus, somewhat decurrent gills, ovoid spores and basidia longer than those of H. harperi. Finally, the species concept within Pseudoclitocybe and Pogonoloma is discussed and descriptions of the most representative species are provided.