This study focuses on Eriocaulon nudicuspe , an endangered herbaceous plant endemic to Japan, aiming to analyze the composition of its endophytic fungi and evaluate the antioxidant capacity of fungal isolates. E. nudicuspe samples were collected from three Japanese marshes: Yanami, Kamitaka, and Onshinji. Fungi were isolated using the tissue block method and identified based on morphological and molecular characteristics. The...