Rhodocybe formosa (Agaricales, Entolomataceae): new collections, molecular data and synonymy, and Rhodocybe griseonigrella comb. nov.

Rhodocybe formosa (sect. Rhodocybe), a species so far known only from Spain, is here reported from Italy. A detailed description, including also macrophotographs, microphotographs and drawings together with a phylogenetic analysis of the ITS sequences, are provided. According to the molecular comparison of the type collections, R. minutispora, a species recently described on the basis of collections from Spain, is a synonym of R. formosa. Clitopilus griseonigrellus is recognized as a distinct species and recombined in Rhodocybe. A key to the European species of Rhodocybe sect. Rhodocybe is provided.