New additions to Ericboehmia and Psiloglonium (Hysteriaceae, Hysteriales) based on morphology and multilocus phylogeny.

Hysteriaceae is a taxonomically diverse family of ascomycetes, and continued taxonomic studies are improving our understanding of its species diversity and phylogenetic relationships. Two new species of Hysteriaceae, Ericboehmia guizhouensis sp. nov., and Psiloglonium yunnanense sp. nov., are described from southwestern China, delineated through an analysis of both morpho-anatomical characteristics and multilocus phylogenetic analyses based on ITS, LSU, SSU, tef1-α, and rpb2 sequence data. Both species share key morphological characteristics typical of Hysteriaceae, while their differentiation from previously described congeners was substantiated by comparative morphological characters and phylogenetic analyses. Comprehensive morphological descriptions, detailed illustrations, and a multilocus phylogenetic analysis demonstrating the phylogenetic placements of the new taxa presented. Furthermore, SSU and tef1-α sequence data from additional collections of Psiloglonium macrosporum, are provided in this study. These findings expand the known diversity of Ericboehmia and Psiloglonium and enhance our understanding of their taxonomic framework and evolutionary relationships based on morphology and multilocus phylogeny.