A Taxonomic and Phylogenetic Contribution on Inosperma Section Inosperma (Agaricales, Inocybaceae) in Europe: Calamistratum and Geraniodorum Groups

The aim of this study is to carry out a taxonomic revision of the groups Calamistratum and Geraniodorum of the genus Inosperma sect. Inosperma in Europe. For this purpose, a multigenic phylogenetic analysis was carried out using the ITS, LSU, RPB1 and RPB2 markers, covering a total of 111 sequences, including those generated from the existing type-material collections. This analysis led to the recognition of nine clades or terminal groups for the European continent, correlating with nine morphological species. Three of them, I. calamistratum, I. neohirsutum sp. nov. and I. turietoense sp. nov., are distributed in humid and temperate forests, whereas I. geminum sp. nov., I. geraniodorum, I. gracilentum sp. nov., I. praetermissum comb. nov., I. subhirsutum and I. veliferum seem to be restricted to the colder altimontane, boreal and alpine climates. It is concluded that the study of morphological and ecological characteristics allows the recognition of species without the need for an often-subjective interpretation of organoleptic characteristics. Inocybe hirsuta is considered a synonym of Inosperma calamistratum, Inosperma praetermissum as a different species from I. calamistratum, and Inocybe geraniodora var. gracilenta f. salicis-herbaceae as a synonym of I. praetermissum. Four new species and one new combination are proposed. A key for the recognition of the European species is provided. Illustrations and photographs of macro- and micromorphological characters and SEM spores of all species are presented.