Introducing a new species, Vaginatispora acrostichi (Lophiostomataceae), based on morphology and multigene phylogeny

Vaginatispora acrostichi sp. nov. was isolated from submerged stems of Acrostichum aureum (Pteridaceae) collected from the mangrove habitats of Pranburi District, Prachuap Khiri Khan, Thailand. Phylogenetic analyses based on the combined dataset of LSU, SSU, ITS, tef1-α, rpb2, and β-tub sequences placed the novel species within Vaginatispora. Vaginatispora acrostichi formed a well-supported sister clade with V. lignicola but differs from it morphologically and phylogenetically. Vaginatispora acrostichi is distinguishable from V. lignicola by ascospore size, septation and colour. The ascospores of V. acrostichi turn light brown at maturity and have a single septum with a minute constriction, while those of V. lignicola appear yellowish at maturity and have 1–3 septa with pronounced constriction. Vaginatispora acrostichi is introduced in this paper as a novel species with a comprehensive description and illustration.