In this study, five aquatic hyphomycetous taxa were collected and isolated from submerged wood in Lancang River located in the northwestern Yunnan Province of China. Phylogenetic analyses based on combined LSU, ITS, tef1α and rpb2 sequence matrix indicated that those five taxa belonging to Distoseptispora (Distoseptisporaceae), and they can be recognized as four species which two are introduced as new species (Distoseptispora euseptatensis and D. yunnanensis) and two are identified as D. aquatica and D. tectonae. Two isolates of the new species Distoseptispora euseptatensis formed a distinct clade among Distoseptispora species (basal to D. suoluoensis and D. bambusae) with good support (ML 100%, MP 100%, BI 1.00 PP). Distoseptispora yunnanensis clustered together with D. euseptatensis, but they are difference in the size of conidiophore and conidia. Corresponding illustrations, descriptions and phylogenetic evidences are provided to justify the placement of our newly collected Distoseptispora taxa.

Microfungi associated with woody plants on the Qinghai–Tibet Plateau (QTP) were investigated, and four collections associated with Potentilla fruticosa were obtained from Gansu and Qinghai provinces in China. Morphologically, they line well with Lentitheciaceae in having subglobose to globose ascomata with brown setae on the papilla but can be distinguished from other genera by its superficial, globose, black, thick-walled ascomata, and fusiform, hyaline (rarely pale brown), one-septate ascospores, surrounded by an entire mucilaginous sheath. The phylogenetic analyses based on a combined SSU, ITS, LSU and TEF1-α sequence data showed that four isolates formed a monophyletic clade among the genera of Lentitheciaceae, and present as a distinct lineage (sister clade to Darksidea). Therefore, we introduce a new genus Crassoascoma, with C. potentillae as the type to accommodate these taxa. Detailed description and illustration are provided, and the establishment of new taxa is justified with morphology and phylogenetic evidence.