Plant debris are habitats favoring survival and multiplication of various microbial species. During continuing mycological surveys of saprobic microfungi from plant debris in Yunnan Province, China, several Corynespora-like and Dendryphiopsis-like isolates were collected from dead branches of unidentified perennial dicotyledonous plants. Four barcodes, i.e., ITS, LSU, SSU and tef1-α, were amplified and sequenced. Morphological studies and multigene phylogenetic analyses by maximum likelihood and Bayesian inference revealed three new Corynespora species (C. mengsongensis sp. nov., C. nabanheensis sp. nov. and C. yunnanensis sp. nov.) and a new Kirschsteiniothelia species (K. nabanheensis sp. nov.) within Dothideomycetes, Ascomycota. A list of identified and accepted species of Corynespora with major morphological features, host information and locality was compiled. This work improves the knowledge of species diversity of Corynespora and Kirschsteiniothelia in Yunnan Province, China.

Three new species of Helminthosporium, H. nabanhensis, H. sinensis and H. yunnanensis collected on dead branches of unidentified plants in Xishuangbanna, China, were proposed by morphological and molecular phylogenetic analysis. Phylogenetic analysis of the combined data of ITS-SSU-LSU-TEF1-RPB2 sequences was performed using Maximum-Likelihood and Bayesian Inference, although H. nabanhensis and H. sinensis lack the RPB2 sequences. Both molecular analyses and morphological data supported H. nabanhensis, H. sinensis and H. yunnanensis as three independent taxa within the Massarinaceae.

A new anamorphic fungus,Corynespora chinensis , is described and illustrated from a specimen collected on dead branches of an unidentified broadleaf tree in Hainan, China. The fungus is characterized by its terminal, monotretic conidiogenous cells with catenate, obclavate, pale brown, smooth, 1–5-distoseptate conidia.

Zasmidium sinense , collected from dead branches of an unidentified broadleaf tree in Guangdong Province, China, is described and illustrated. The new species is characterized by differentiated conidiophores having a branched head with polyblastic, sympodial, conspicuously cicatrized conidiogenous cells that produce solitary, obovoid to clavate, pale brown, smooth, 1(–2)‐euseptate conidia.