Abstract
BACKGROUND: Crepidotus is an essential group of saprotrophic fungi within ecosystems and exhibits a widespread global distribution. In China, approximately 80 species have been discovered, most of them being collected from humid monsoonal climate zones of China. NEW INFORMATION: In this paper, we report on several specimens of Crepidotus collected from the Inner Mongolia Autonomous Region, an arid area of China characterised by a continental climate. Morphological and phylogenetic analyses revealed two taxa: the first record for China of Crepidotusstenocystis Pouzar and a new species Crepidotuscinereofuscus sp. nov. C.stenocystis is a wood-inhabiting saprotrophic fungus, belonging to C.subg.Dochmiopussect.Sphaeruli Hesler & Smith because of the presence of clamp connections and subglobose verrucose basidiospores. Phylogenetically, the Chinese sequence of C.stenocystis formed a strongly-supported clade with other reliable sequences. C.cinereofuscus is a soil-saprotrophic fungus, classified in C.subg.Dochmiopussect.Autochthoni Consiglio & Setti because of its smooth basidiospores and clamp connections. Phylogenetic analyses confirmed that C.cinereofuscus is closely related to Crepidotusclavocystidiatus M.H. Han, Q. Na & Y.P. Ge, but it is clearly separated and formed a distinct clade. C.cinereofuscus is also different from C.clavocystidiatus in morphological characteristics. Detailed species descriptions, photographs and line drawings of these taxa are provided. This study enhances our understanding of Crepidotus diversity in the Inner Mongolia Autonomous Region, raising the total number of Crepidotus species reported from this region to seven.