Abstract
Freshwater ascomycetes are fungi that play an important role in the decomposition of submerged plant debris in freshwater habitats. At present, approximately 3000 species of ascomycetes have been described from freshwater habitats. However, the number of fungi in freshwater habitats in South Korea is small, and many species are still completely unknown. During investigations of freshwater ascomycetes in South Korea, three Dothideomycetes strains and seven Sordariomycetes strains were collected. Based on morphological and multigene phylogenetic analyses, one new species of Neopestalotiopsis was delimited: Neopestalotiopsis koreensis. In addition, Chaetocapnodium philippinense, Curvularia plantarum, Engyodontium rectidentatum, Fusarium arcuatisporum, Microdochium yunnanense, Septoriella verrucispora, Stephanonectria chromolaenae, and Trichoderma amoenum, are reported for the first time from South Korea. Herein, detailed descriptions and illustrations of the morphological characteristics of these species are provided.