The Crepidotaceae (Basidiomycota, Agaricales): phylogeny and taxonomy of the genera and revision of the family based on molecular evidence

Abstract

Advances in phylogenetic systematics have clarified the position of most major homobasidiomycete lineages. In contrast, the status of the Crepidotaceae, a historically controversial family of dark-spored agarics, remains unaddressed. In this paper, current morphology-based classifications of the agaric genera of the Crepidotaceae were evaluated by parsimony and constraint analyses of sequence data from the nuclear large subunit rDNA. Taxa analyzed included the type species for each agaric genus allied in the family by Singer: Crepidotus, Simocybe, Pleurotellus, Tubaria, and Melanomphalia. Contrary to traditional classifications, results suggest that the crepidotoid fungi have three separate origins within the euagarics. The Crepidotaceae sensu stricto (s.s.) includes Crepidotus and Simocybe and represents a separate lineage of dark-spored euagarics. Pleurotellus is congeneric with Crepidotus. Results indicate the exclusion of both Tubaria and Melanomphalia from the Crepidotaceae s.s. Tubaria is allied with the strophariaceous taxa Phaeomarasmius and Flammulaster, while Melanomphalia has arisen from within a lineage of light-spored omphalinoid euagarics representing an independent acquisition of basidiospore pigmentation. Other pleisiomorphic and newly uncovered synapomorphic characters are discussed in detail along with the taxonomic status of each genus, and a revised family description is provided.