Phaeobotryon ormosiae (Botryosphaeriaceae, Botryosphaeriales), a new species from Ormosia semicastrata in Guizhou Province, China

Phaeobotryon is a widely distributed fungal genus commonly associated with woody stems, playing important ecological roles in forest ecosystems. During an investigation of tree trunk diseases in Guizhou Province, China, we isolated three strains of this genus from Ormosia semicastrata. Based on integrated morphological and phylogenetic analysis (using ITS, tef1-α, and LSU gene loci), a novel species, Phaeobotryon ormosiae sp. nov., is described and illustrated. The phylogenetic analysis revealed that P. ormosiae sp. nov. forms a well-supported clade (ML/BI= 99/0.99) distinct from other known Phaeobotryon species (sequence differences of 0.86% in ITS, 0.37% in LSU, 4.50% in tef1-α). This study provides a comprehensive taxonomic characterization, including detailed morphological descriptions, high-resolution microscopic illustrations, and molecular sequence data deposited in public databases. Our findings expand the known species diversity of the genus Phaeobotryon.