Abstract
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.