Taxonomy of a novel and a new geographical record of Nigropunctata species (Pallidoperidiaceae) on Bambusa vulgaris from northern Thailand

Nigropunctata is an understudied genus of bambusicolous fungi, and its diversity in Thailand remains poorly known. This study aimed to investigate species of Nigropunctata associated with bamboo in Thailand using morphological observations along with multi‐locus phylogenetic analyses of the internal transcribed spacer (ITS), large subunit (LSU), RNA polymerase II second largest subunit ( rpb2 ), and β‐tubulin ( β‐tub ). The genus Nigropunctata is characterized by brown to dark brown, cylindrical, aseptate, and guttulate ascospores that occasionally possess a germ slit. Members of this genus are saprobes, typically isolated from dead bamboo branches. During our study, fungi on Bambusa samples were collected from Thailand, which fit the morphological species concept of Nigropunctata by sharing similar ascospore features. This approach facilitated the identification of a new species, Nigropunctata pseudohydei , and a new geographical record for Nigropunctata complanata. Nigropunctata pseudohydei is distinguished from its closest relative in phylogenetic analyses based on ITS, LSU, rpb2 , and β‐tub sequences, as well as by clear genetic distance differences, and it also differs by having smaller ascomata but larger asci and larger ascospores. Additionally, our isolate of N. complanata exhibits a morphology closely resembling that of the holotype, thereby confirming its identification and providing the first record of N. complanata from Thailand.