Abstract
Approximately 77% of Pseudochaetosphaeronema species have been reported from China and Thailand in terrestrial habitats. We collected and isolated fruiting bodies of ascomycetous fungi in Yunnan Province, China, from dead branches of Hevea brasiliensis. Integrating morphology with phylogenetic analyses of combined ITS, LSU, SSU, and tef1-α sequence data, the strains were identified as a new species (Pseudochaetosphaeronema heveae), two new host records (P. baoshanense and P. chiangraiense), and a new collection (P. xishuangbannaense). Descriptions, illustrations, phylogenetic analysis results, and morphological comparisons with allied taxa of the four Pseudochaetosphaeronema species are provided. These findings expand the known diversity and host associations of Pseudochaetosphaeronema. In addition, based on morphological characteristics and molecular phylogenetic data, P. hongheense is synonymized under P. baoshanense.