Ossicaulis yunnanensis sp. nov. (Lyophyllaceae, Agaricales) from southwestern China

Ossicaulis is a small genus in the family Lyophyllaceae. Two known species, O. lachnopus, and O. lignatilis, are distributed in north temperate regions. The third taxon, O. yunnanensis sp. nov., is described from the alpine belt of subtropics of southwestern China, and this genus is also reported for the first time from China. Morphologically, the new species is characterized by its whitish basidiomata and very small basidiospores. Molecular analyses from the nuclear rDNA internal transcribed spacer region (ITS) show that the subtropical alpine species is distinct from hitherto known Ossicaulis species and has a close relationship to O. lachnopus.