Clitopilus abprunulus, a new species from North Macedonia with notes on C. ravus and pleuromutilin producing taxa

In this study, Clitopilus abprunulus (Entolomataceae, Agaricales) is described as a new species based on collections from North Macedonia with both morphological and molecular evidence. It differs from other species in Clitopilus by its grayish pileus, eccentric stipe, and inflated cells in the lamellar trama. The nuclear ribosomal internal transcribed spacer (ITS) regions were sequenced and used for phylogenetic analyses. The results based on ITS sequences using both Maximum Likelihood (ML) and Bayesian Inference (BI) methods indicated that the new species was distinct from other species. The systematic position of the pleuromutilin-producing taxa in Clitopilus was elucidated, it was found that all of them were clustered into a single lineage within C. section Scyphoides. In addition, an epitype for C. ravus is designated, and the shape changes of the basidiospores of this taxon during their development are discussed.