Byssosphaeria vaginata, a new species of Melanommataceae from Magnolia officinalis in Sichuan Province, China

During an investigation of ascomycetous fungi on Magnolia officinalis (Magnoliaceae) in Sichuan Province, Southwest China, a novel species, Byssosphaeria vaginata, is introduced. The taxonomic placement of the species was confirmed based on morphology and muti-gene phylogeney. Though our new species resembles B. clematidis, it differs from the type species (B. clematidis) in having larger ascomata with pale yellowish pigment around the pore and wider and shorter ascospores with clear mucilaginous sheaths.

The phylogenetic analysis based on LSU, SSU, ITS, and tef 1-α sequence data generated from Maximum Likelihood (ML) and Bayesian analyses (BI) indicates that B. vaginata forms a robust clade with B. clematidis nested among the species of Melanommataceae within Pleosporales. Comprehensive descriptions and detailed illustrations are provided. In addition, the relationships of Byssosphaeria vaginata to other related species with a mucilaginous sheath in Melanommataceae are discussed based on comparative morphology and phylogenetic evidence.