<i>Tricholoma alpinum</i>, sp. nov., under five-needle pines in alpine and subalpine zones in Japan

Alpine regions in Japan are characterized by the Siberian dwarf pine, <i>Pinus pumila</i>. Although these regions are conserved as national parks due to their unique biome, few reports of the fungal biota are available. We examined mushroom fungi under such vegetation and found a unique yellowish-capped <i>Tricholoma</i> species. Multilocus molecular phylogenetic analyses and morphological observation of specimens showed that the <i>Tricholoma</i> species is very similar to <i>T. fumosoluteum</i> known in North America. The Japanese yellowish-capped <i>T</i>. aff. <i>fumosoluteum</i> had larger basidiospores and basidia and shorter pileipellis hyphae compared with <i>T. fumosoluteum</i>. Therefore, we describe the Japanese entity as a new species, <i>T. alpinum</i>.