A phylogenetic overview of , with descriptions of nine new species and four new combinations.

Nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) sequence data from eight type specimens of previously described species were obtained. Phylogenetic analysis of ITS and partial nuc 28S rDNA data revealed as paraphyletic splitting into two monophyletic groups, which we recognize as the genera and . We accept 14 and nine species, provide the first sequences of 13 of these, and describe six new species of and three new species of . We transfer three species of into , one into , and treat and as synonyms of can be distinguished from by the generally larger fleshier basidiomata with a tricholomatoid or amanitoid stature and yellowish to tawny brown pileus and often similarly colored stipe. Most species have cheilo- and pleurocystidia. Species of are small, collybioid or mycenoid, lack cystidia, and the pileus and often upper stipe are purplish gray. Both genera parasitize basidiomata of other agarics.