Species diversity of edible mushrooms III: new species of Laccaria (Agaricales, Basidiomycota) from southwestern China based on morphology and multilocus phylogeny.

Species of Laccaria (Hydnangiaceae, Agaricales, Basidiomycota) are an important group of ectomycorrhizal fungi with significant ecological and economic value. They are widely distributed. This study describes two new species of Laccaria based on morphological characters and molecular data. Laccaria daliensis is characterized by a pale orange to grayish orange pileus, grayish orange lamellae, and a stipe. Laccaria violaceonana is characterized by medium-sized, deep purple basidiomata and an equal stipe with an enlarged base. Phylogenetic analysis based on a combined dataset of the internal transcribed spacer ITS1-5.8S-ITS2 rDNA (nrITS), large subunit nuclear ribosomal RNA gene (nrLSU), RNA polymerase II subunit 2 (rpb2), and translation elongation factor 1-α (tef1-α) was used to provide further evidence for species delimitation. The results showed that nine Laccaria specimens formed four well-supported clades, representing two new species, Laccaria daliensis and L. violaceonana, and two known species, L. acanthospora and L. pumila. Detailed descriptions, illustrations, and phylogenetic analysis results of these species are provided, and the new species are compared with closely related taxa.