Two novel species of Neomonodictys and Phaeoisaria (Pleurotheciaceae, Pleurotheciales) from freshwater habitats in China.

During a recent survey of lignicolous freshwater fungi in Guizhou Province, China, two fungi were collected from submerged woody substrates and were preliminarily identified as members of the family Pleurotheciaceae. Comprehensive morphological examinations, combined with multi-locus phylogenetic analyses based on ITS, LSU, SSU, and rpb2 sequence data, revealed that both specimens represent previously undescribed taxa. In this study, we provide detailed morphological descriptions, illustrations, and phylogenetic evidence to support the establishment of two novel species, Neomonodictys subtropicus and Phaeoisaria guiyangensis. The discovery of these taxa contributes to the growing body of knowledge on the diversity and taxonomy of freshwater fungi in Southwest China. It also emphasizes the ecological importance of Pleurotheciaceae in lignicolous freshwater habitats and highlights the potential for discovering novel fungal lineages in underexplored regions such as Guizhou Province.