The Clitocybaceae is a recently established family. Currently, the infrafamilial divisions and relationships within the family are vague due to limited sampling and genes employed for phylogenetic analysis. Some mushrooms of the family contain the neurotoxic muscarine, which has caused many severe and even deadly poisonings worldwide. However, the taxonomic distribution and evolution of the toxin within the family is largely unknown. In this study, phylogenetic analyses based on nucleotide sequences of ITS and of six molecular loci (ITS, LSU, TEF1, RPB1, RPB2 and ATP6), plus a phylogenomic analysis based on 485 single-copy orthologous genes, were performed to reconstruct the framework of Clitocybaceae. BEAST analysis was used to estimate the divergence times within the family. Additionally, biochemical analysis for muscarine was conducted of 32 representative species. Based on these analyses, an updated classification of Clitocybaceae into six genera (Clitocybe, Collybia, Dendrocollybia, Lepista, Pseudolyophyllum, and Singerocybe) is proposed. The genus Collybia is emended to accommodate four subgenera (Collybia, Crassicybe, Leucocalocybe, and Macrosporocybe). Seventeen new Chinese species and 15 new combinations are proposed. Keys to the genera of Clitocybaceae and the subgenera of Collybia, as well as to the known species of Clitocybe and Collybia subgen. Collybia in China, are presented. In addition, muscarine was detected in 18 species, and these muscarine-containing species formed a major monophyletic clade within Collybia subgen. Collybia. Finally, our phylogenetic, phylogenomic, chemotaxonomic and molecular dating results indicate that the Clitocybaceae is a natural group estimated to have arisen some 60 million years ago, and in this family, muscarine has evolved only once circa 20 million years ago without later losses.

Two new species of Trechispora indigenous to southern China, T. laxa and T. tongdaoensis, are described and illustrated, and the first record of T. khokpasiensis in China is reported. Molecular phylogenetic analyses of the concatenated nuclear rDNA ITS1–5.8S–ITS2 and nuclear large subunit sequences supported the inclusion of the three species within the Trechispora clade, together with species formerly classified in Scytinopogon. The new species are similar in micromorphology to species of Trechispora (as traditionally circumscribed) but are distinguished by having coralloid basidiomata. A key to the known coralloid Trechispora species in China is provided.

Phylogenetically, the genera Cuphophyllus, Ampulloclitocybe and Cantharocybe are treated as basal in the family Hygrophoraceae, despite weak support. However, the exact phylogenetic positions of the three genera have remained unresolved, and taxa related to these genera are poorly known. In this study, a new clitocyboid genus Spodocybe was proposed based on multigenic phylogenetic inference datasets and morphological evidence. The analyses of ITS as well as two combined datasets ITS-nrLSU-rpb2 and ITS-nrLSU-rpb1-rpb2-tef1-α-atp6 supported that (1) Spodocybe formed a well-supported monophyletic clade; and (2) sisters Spodocybe and Ampulloclitocybe, along with Cantharocybe and Cuphophyllus also formed a monophyletic lineage, as sister to the rest of the Hygrophoraceae. Meanwhile, two new species, namely S. rugosiceps and S. bispora, from southwestern China, were documented and illustrated. These results support the new proposed genus Spodocybe, and that Spodocybe, Ampulloclitocybe, Cantharocybe and Cuphophyllus should be retained in the Hygrophoraceae as a new subfamily Cuphophylloideae.

Numerous severe cases of neurotoxic mushroom poisoning worldwide are caused by ibotenic acid and muscimol produced by specific species belonging to section Amanita of the genus Amanita . Recent studies have demonstrated that both toxins are produced through the ibotenic acid biosynthetic gene cluster ( ibo BGC) in these species. In addition to these two toxins, section Amanita is also thought to include several species producing another neurotoxic compound, muscarine. However, the taxonomic distribution and evolutionary history of these toxins within the section remain poorly understood. In this study, phylogenetic analyses based on nucleotide sequences of two loci (ITS and LSU) and five loci (ITS, LSU, RPB2 , TEF1 , and TUB2 ), together with a phylogenomic analysis using 467 single-copy genes, were conducted to reconstruct the phylogenetic framework of section Amanita. BEAST analysis was used to estimate divergence times within the section. Gene identification of the ibo BGC was conducted using 25 Amanita genomes, followed by phylogenetic analyses of each ibo gene. Biochemical analysis of muscarine was performed on 31 representative species. Based on these analyses, ibo genes were detected in 21 species forming a major monophyletic clade within the section Amanita, whereas muscarine was detected in eight species that constituted a small subclade nested within this clade. Finally, our phylogenetic, phylogenomic, chemotaxonomic, and molecular dating results indicate a monophyletic distribution of the ibo BGC and muscarine within the section Amanita, with independent origins approximately 28 million years ago (Mya) and 15 Mya, respectively, and no evidence of subsequent losses.

Laccaria is a large genus within the family Hydnangiaceae, and many potential species remain to be discovered in China. The present study describes three new species, L. carminostipes, L. mangshanensis and L. sinolateritia, and reports two new records, L. japonica and L. versiforma, which were originally discovered in Japan and Korea, respectively. These species were collected from subtropical mixed forests and identified based on morphological and phylogenetic evidence. Our phylogenetic analysis of the concatenated nucleotide sequences of ITS, LSU, TEF1 and RPB2 demonstrated that the three new species each formed a distinct clade, clearly separated from other known Laccaria species. A detailed description and illustrations of these species are also provided.