Species Diversity of Edible Mushrooms I—Four New Laccaria Species from Yunnan Province, China

As symbiotic mycorrhizal associates, species within the genus <i>Laccaria</i> play pivotal roles in forest ecosystems, specifically forming ectomycorrhizal relationships with the root systems of various plants. Some <i>Laccaria</i> species are recognized for their edibility, holding potential as a sustainable food source in the context of future food security and dietary diversification. In this study, the species diversity of <i>Laccaria</i> in Yunnan was investigated, and four novel species were identified. Their taxonomical positions and phylogenetic affinities were confirmed through phylogenetic analysis based on ITS, nrLSU, <i>tef</i>1-α, and <i>rpb</i>2 sequence data. Macro- and micro-morphological characteristics of the new species are also given here. <i>Laccaria brownii</i> sp. nov. has a dark to slightly desaturated orange pileus, stipe context broadly fistulose and soft orange, and relatively smaller cheilocystidia and pleurocystidia. <i>Laccaria orangei</i> sp. nov. has a hemispherical to paraboloid pileus, abundant narrowly clavate, flexuose, and branched cheilocystidia. <i>Laccaria ruber</i> sp. nov. pileus is red on the margin, clearly striate on the pileus surface, basidia clavate, mostly four-spored, rarely two-spored. <i>Laccaria stipalba</i> sp. nov. stipe surface is white, long sterigmata (4-13 μm × 2-3 μm), pleurocystidia narrowly clavate to subclavate, flexuose or mucronate, rarely branch. The descriptions, illustrations, and phylogenetic analysis results of the new taxa are provided. In addition, the new taxa are compared with closely related taxa.