Two New and One First Recorded Species of Xylaria Isolated from Fallen Leaves in Hainan Tropical Rainforest National Park in China

Xylaria is a widely distributed genus in the Ascomycota phylum that can decompose wood. It is an essential decomposer in ecosystems and a source of bioactive secondary metabolites. Based on morphological characteristics and molecular evidence, this article thoroughly describes two new species discovered on the fallen leaves in Hainan Tropical Rainforest National Park, along with illustrations and comparisons with similar species. Xylaria diaoluoshanensis is characterized by filamentous stromata with long infertile apexes, ascospores sometimes with non-cellular appendages. Xylaria fulvotomentosa differentiates itself from other Xylaria species that grow on fallen leaves by its stroma surface, being yellow tomentose. These two new species of the genus Xylaria were found by phylogenetic analysis using the ITS-beta-tubulin-RPB2 sequence dataset. Furthermore, a species first discovered in China, X. petchii, is described. Finally, a search table for 44 species related to fallen leaves and petioles in the world is established.