Abstract
Microthyriaceae is typified by the sexual genus Microthyrium, with eight asexual genera. Three interesting isolates were collected during our investigation of freshwater fungi from the wetlands in Guizhou Province, southwest China. Three new asexual morphs are identified. Phylogenetic analyses using ITS and LSU gene regions revealed the placement of these isolates in Microthyriaceae (Microthyriales, Dothideomycetes). Based on the morphology and phylogenetic evidence, two new asexual genera, Paramirandina and Pseudocorniculariella, and three new species, Pa. aquatica, Pa. cymbiformis, and Ps. guizhouensis, are introduced. Descriptions and illustrations of the new taxa are provided, with a phylogenetic tree of Microthyriales and related taxa.