Three new species of Xylaria on fallen leaves in Hainan Province of China are described and illustrated, based on morphological and molecular evidence. Xylaria hedyosmicola is found on fallen leaves of Hedyosmum orientale and featured by thread-like stromata with a long sterile filiform apex. Phylogenetically, X. hedyosmicola is closely related to an undescribed Xylaria sp. from Hawaii Island, USA and morphologically similar to X. vagans. Xylaria lindericola is found on fallen leaves of Lindera robusta and characterised by its subglobose stromata and a long filiform stipe. It is phylogenetically closely related to X. sicula f. major. Xylaria polysporicola is found on fallen leaves of Polyspora hainanensis, it is distinguished by upright or prostrate stromata and ascospores sometimes with a slimy sheath or non-cellular appendages. Xylaria polysporicola is phylogenetically closely related to X. amphithele and X. ficicola. An identification key to the ten species on fallen leaves in China is given.

Two new species, Hypoxylon larissae and Hypoxylon jianfengense, are described and illustrated on the basis of a combination of morphological and molecular characters from China. Hypoxylon larissae was collected from southwest China (Yunnan province), while H. jianfengense was collected from southern China (Hainan province). Hypoxylon larissae is characterized by effused-pulvinate stromata, Orange (7) and Luteous (12) pigments extracted in 10% KOH and light brown to dark brown ascospores with straight germ slit. It is phylogenetically and morphologically closely related to H. fenderi. Hypoxylon jianfengense is distinguished by tubular to long tubular perithecia, Dark Green (21), Isabelline (65) and Dull Green (70) pigments extracted in 10% KOH and conspicuous coil-like perispore ornamentation. Hypoxylon jianfengense clustered with H. invadens and H. trugodes in a well-supported clade. Phylogenetic analyses of multi-gene sequences (ITS-LSU-RPB2-TUB2) support the recognition of the taxa as distinct.

The Hypoxylon species play an important ecological role in tropical rainforest as wood-decomposers, and some might have benefical effects on their hosts as endophytes. The present work concerns a survey of the genus Hypoxylon from Hainan Tropical Rainforest National Park of China. Four new species: H. wuzhishanense, H. hainanense, H.chrysalidosporum, and H.cyclobalanopsidis, were discovered based on a combination of morphological characteristics and molecular data. Hypoxylon wuzhishanense is characterized by Rust pulvinate stromata, amyloid apical apparatus and brown ascospores, with most of the perispore being indehiscent in 10% KOH. Hypoxylon hainanense has effused–pulvinate and Violet stromata, amyloid apical apparatus, light-brown to brown ascospores with straight germ slit and dehiscent perispore. Hypoxylonchrysalidosporum is distinguished by glomerate to pulvinate stromata, highly reduced or absent inamyloid apical apparatus, and light-brown to brown ascospores with very conspicuous coil-like ornamentation. Hypoxyloncyclobalanopsidis has Livid Purple pulvinate stromata, highly reduced amyloid apical apparatus, faint bluing, brown ascospores and dehiscent perispore, and it grows on dead branches of Cyclobalanopsis. Detailed descriptions, illustrations, and contrasts with morphologically similar species are provided. Phylogenetic analyses inferred from ITS, RPB2, LSU, and β-tubulin sequences confirmed that the four new species are distinct within the genus Hypoxylon.