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.

Xylaria, a large and cosmopolitan genus of Ascomycota, plays an important ecological role in forest ecology as wood-decomposers, and serve as a source of bioactive secondary metabolites. The present work concerns a survey of Xylaria from Southwest China. Four new species of Xylaria with pale-colored ascospores associated with fallen fruits and seeds are described and illustrated based on morphological and phylogenetic evidences. The phylogeny inferred from a combined dataset of ITS-RPB2-β-tubulin sequences supports these four species as distinct species. The four new taxa, namely Xylariarogersii, X. schimicola, X. theaceicola, and X. wallichii, are compared and contrasted against morphologically similar species. A dichotomous identification key to all the accepted species of Xylaria associated with fallen fruits and seeds is given.

Two new species of Diatrype collected in northeast China are described and illustrated based on morphological and molecular evidence. Diatrype larissae from Heilongjiang Province is characterised by having 3–6 perithecia in a stroma, asci polysporous, ascospores allantoid, aseptate, slightly or moderately curved, subhyaline. Diatrype betulaceicola from Inner Mongolia has large stroma with 5–14 perithecia, perithecium immersed, asci polysporous, long-stalked, ascospores allantoid, aseptate, slightly curved, subhyaline. The phylogenies inferred from the data set of nrDNA ITS1-5.8S-ITS2 (ITS) and beta-tubulin (β-tubulin) supported the two new species both as members in the genus Diatrype and distinct species. The morphological similarities and dissimilarities of the new species with phylogenetically close relatives are discussed. A dichotomous identification key to the Diatrype spp. known from China is proposed.

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-β-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.

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.

Xylaria is a large and complex genus of macrofungi, playing a critical role in ecosystems as decomposers and possessing antimicrobial, anticancer, and antioxidant properties. This paper described two new Xylaria species discovered on fallen leaves in Hainan Tropical Rainforest National Park, based on morphological characteristics and genetic sequences. Detailed color illustrations and comparisons with similar species were provided. The main characteristics of X. acifer included long, needle-shaped stromata, ellipsoid to fusoid ascospores, and prominent non-cellular appendages. The stromata of X. tuberculosa had an aggregated, knobby fertile part, with smaller ascospores also featuring non-cellular appendages. Additionally, a key to 46 Xylaria species associated with fallen leaves and petioles worldwide was established.