Two new species of Parastagonospora and a new species of Phaeoseptoriella (Phaeosphaeriaceae, Pleosporales) from grasslands in Yunnan Province, China.

During our investigation of microfungi on grasslands in Yunnan Province, China, three new fungal taxa associated with grasses were collected. Morphological observations and phylogenetic analyses of the combined SSU, LSU, ITS, tef1-α, and rpb2 loci based on maximum likelihood and Bayesian inference were used to reveal the taxonomic placement of these fungal taxa. This study introduces Parastagonosporayunnanensis, Para.zhaotongensis, Phaeoseptoriellapoaceicola. Parastagonosporayunnanensis is characterized by ampulliform or globose to subglobose conidiogenous cells, with conidia that are cylindrical to subcylindrical, 0-1-septate, rounded at the apex and slightly truncate at the base. Parastagonosporazhaotongensis features similar globose to subglobose conidiogenous cells but with 0-3-septate, cylindrical to subcylindrical conidia. Phaeoseptoriellapoaceicola is distinguished by its globose to subglobose conidiogenous cells and phragmosporous conidia that are initially hyaline, turn pale yellowish at maturity, and are 7-septate, cylindrical to subcylindrical, either straight or slightly curved. These discoveries underscore the significance of exploring and accurately identifying fungal taxa within Ascomycota, highlighting the species richness and potential for new species discoveries in grass-based habitats. The findings from this study expand our understanding of the taxonomy and phylogeny of grassland-associated Ascomycota, providing a foundation for further ecological and taxonomic studies of these fungi within their natural environments.