Abstract
During an investigation into species diversity of lignicolous freshwater fungi from the plateau lakes in Yunnan Province, China, a hyphomycetous fungus was collected from Dianchi Lake. The new isolate was placed in Appendopyricularia as a sister taxon of Appendopyricularia juncicola within Barbatosphaeriaceae based on the phylogenetic analysis of combined ITS and LSU sequence data. The fungus is characterized by acrogenous, fusoid, guttulate conidia that are 3–4 septate and have a flexuous central apical appendage. It exhibits more pronounced guttulate appendages and more prominent denticle sporulation structure. Therefore, Appendopyricularia guttulata is introduced as a new species based on morphological characteristics and phylogenetic evidence. The detailed description and illustrations of the new species are provided, as well as the morphological comparison with similar taxa.