The wild edible mushroom Pleurocollybia cibaria from Peru is a species of Gerhardtia in the Lyophyllaceae (Agaricales)

Pleurocollybia cibaria is a wild edible mushroom sold in markets in Peru. The genus Pleurocollybia shares a phylogenetic alliance with the Tricholomatineae in the family Biannulariaceae (= Catathelasmataceae), however, no taxonomic investigations of P. cibaria have been performed since it was originally described over 50 years ago. Here we employ a molecular phylogenetic analysis including P. cibaria and compare a modern extant collection with that of the holotype to confirm its systematic placement and provide an updated taxonomic description of the species. Fresh material of P. cibaria was compared with that of the holotype collection using light microscopy and scanning electron microscope methods. Molecular phylogenetic analyses of the internal transcribed spacers (ITS) of the nuclear ribosomal RNA tandem repeat were performed. Microscopic analyses of fresh and type material of P. cibaria support their conspecificity. For the first time, we reveal the presence of minutely verruculose basidiospores and cyanophilic and siderophilous bodies in the basidia of P. cibaria, which support a morphological alliance with the genus Gerhardtia (family Lyophyllaceae), not Pleurocollybia (family Biannulariaceae). Morphological and molecular data support the transfer of P. cibaria to the genus Gerhardtia.