Abstract
An Ascomycetous species was found from decaying woody stems in Guizhou, China. Morphologically, the fungus can be assigned well in Tremateia in having immersed ascomata, cellular pseudoparaphyses and muriform ascospores, but it differs from other species in having the 3–7 transverse septa ascospores surrounded by a gelatinous sheath. Phylogenetic analyses based on a concatenated dataset of ITS, LSU, SSUand TEF1-α sequence data indicated that the fungus belongs to the genus Tremateia, Didymosphaeriaceae, four taxa formed a monophyletic clade and represent the genus Tremateia with well supported. The new collection formed a distinct lineage and can be recognized as a new species. Therefore, a new species Tremateia murispora is introduced with detailed description and illustration, the notes on its morphologically and phylogenetically related taxa is provided.