A new species of Tulostoma (Agaricaceae, Basidiomycota) from Altay Mountains (Western Siberia, Russia)

A new species of Tulostoma is described based on morphological and molecular data. Phylogenetic analysis based on the ITS1-5.8S-ITS2 and partial 28S nrDNA regions and morphological analysis using the SEM have been carry out. The detailed description of new species, color photos of basidiomata, light microscopy of anatomical characters, and analysis of morphological features in comparison with related species are provided. Morphologically, the new species of Tulostoma is closest to T. kotlabae, and T. lysocephalum and T. morenoi. The new species is distinguished by small, single, greyish-white basidiomata, gleba ocher, spores subglobose, regularly verrucose, with flattened, smoothed, large warts, 4.2 × 5.8 µm in diam. without ornamentation. The new species of Tulostoma and our previously described T. morenoi are endemic to the Altai-Sayan mountain region.