Three novel species and a new record of Pleosporales (Didymellaceae, Roussoellaceae) from China.

We are investigating saprobic Ascomycota in Guizhou Province, China. Fungal specimens collected from dead wood were identified based on morphological characteristics and multi-gene phylogenetic analyses of ITS, SSU, LSU, β-tubulin, ef1-α, and rpb2 sequence data. Three novel species, Neoroussoellaguizhouensis, Roussoellaguizhouensis, and Xenodidymellaguizhouensis, are introduced, along with one new geographical record, Xenoroussoellatriseptata. This study contributes to our understanding of the diversity of Ascomycota in Guizhou Province and the classification in Roussoellaceae.