The circumscription and delimitation of the agaric family Crepidotaceae and related families in the Agaricales have been analysed using nLSU sequence data and direct optimization. The influence of alignment parameters on clade robustness has been explored, and many clades are found to have a low robustness. Nevertheless, based on clades with a high or moderately high robustness to increased gap costs, a few taxonomic changes are suggested: Crepidotaceae has been amended to include Crepidotus, Episphaeria, Simocybe, Pleuroflammula and Inocybe, the latter genus adding the homoplasious character mycorrhization to the family, Pellidiscus is included in Crepidotus, a position supported by micromorphology, two other genera formerly included in the family, Chromocyphella and Phaeosolenia, are excluded, and a new family, Chromocyphellaceae fam. nov., is erected for them based on fruit body shape, microcharacters, and sequences. Monophyly of Tubariaceae as recently circumscribed was not recovered, but tentatively we accept the genera Tubaria and Phaeomarasmius as members of the family.
© The Willi Hennig Society 2009.