Holarctic Species in the Pluteus podospileus Clade: Description of Six New Species and Reassessment of Old Names.

We studied the taxonomy of Pluteus podospileus and similar species using morphological and molecular (nrITS, TEF1-α ) data, including a detailed study of the type collections of P. inflatus var. alneus , Pluteus minutissimus f. major, and P. granulatus var. tenellus . Within the P. podospileus complex, we phylogenetically confirmed six species in Europe, five in Asia, and eight in North America. Based on our results, we recognize P. seticeps as a separate species occurring in North America, while P. podospileus is limited to Eurasia. We describe six new species and a new variety: P. absconditus , P. fuscodiscus , P. gausapatus , P. inexpectatus , P. millsii, and P. notabilis and its variety, P. notabilis var. insignis . We elevate Pluteus seticeps var. cystidiosus to species rank as Pluteus cystidiosus . Based on the holotype of P. inflatus var. alneus , collections of P. inflatus identified by Velenovský, and several modern collections, we resurrect the name P. inflatus . Based on molecular analyses of syntypes of Pluteus minutissimus f. major and a holotype of Pluteus granulatus var. tenellus , we synonymize them under P. inflatus . We also increase our knowledge about the morphology and distribution of P. cutefractus .