A study of type of Pluteus inocybecystis (Pluteaceae, Agaricales) described from Siberia and its synonimization under Homophron spadiceum (Psathyrellaceae, Agaricales)

The type collection of Pluteus inocybecystis A. Petrov deposited in the Mycological herbarium of the Komarov Botanical Institute RAS (LE F) was re-examined. Our morphological observations have revealed that the specimen represents a species from the genus Homophron. Phylogenetically, the sequence of the nrDNA internal transcribed spacer (ITS) of the P. inocybecystis holotype is nested within Homophron spadiceum clade and matches ITS sequences of H. spadiceum with 99.8–100.0 % similarity. Thus, on the basis of morphological and molecular studies, Pluteus inocybecystis is considered as a synonym of Homophron spadiceum.