A preliminary account of a new genus to accommodate Cosmospora vilior and related species

Cosmospora sensu Rossman (Ascomycota, Hypocreales, Nectriaceae) was erected to accommodate nectroid fungi with small, reddish, KOH+, smooth, thin-walled, laterally collapsing when dry, non- or weakly stromatic perithecia. Recently, the group was found to be polyphyletic based on molecular data, and has been segregated into multiple genera. However, not all Cosmospora-like fungi have been treated systematically. Some of these species include C. vilior (Starbäck) Rossman & Samuels and many species often labeled as “Cosmospora sp.” The objectives of this research were to designate an epitype for C. vilior, which has been misapplied based on examination of the type specimen, and determine its phylogenetic position within Cosmospora sensu lato and the Nectriaceae. A multilocus phylogeny was constructed based on six loci (ITS, LSU, RPB1, MCM7, TEF1, and TUB) to estimate the species tree. Results from the phylogenetic analyses indicated that C. vilior forms a monophyletic group with other Cosmopora-like fungi that have an acremonium-like anamorph and that parasitize Eutypa and Eutypella (Diatrypaceae). The group is phylogenetically distinct from other previously segregated genera, and for that reason, a new is described to accommodate these species.