New species, new records and common species of Pluteussect.Celluloderma from northern China.

Wood-rotting fungi are organisms that can decompose wood substrates and extract nutrients from them to support their growth. They play a crucial role in the material cycle of forest ecosystems. The genus Pluteus plays a significant role in wood decomposition. In this study, the morphology and molecular systematics of the sect. Celluloderma of the genus Pluteus were carried out. Pluteusbrunneodiscus was identified as a new species, along with the discovery of two new records, P.cystidiosus and P.chrysophlebius, and a common species, P.romellii. Pluteusbrunneodiscus is characterized by the brown center of the pileus that transitions to white towards the margins, with the surface cracking to form irregular granules. It is typically found in Populus forests growing on decomposing twigs or wood chips. Line drawings, color photographs, and phylogenetic analyses of related species within the genus Pluteus accompany the descriptions of these four species. The analyses are based on ITS + TEF1-α sequence data. Finally, a key for the twenty species within the sect. Celluloderma of the genus Pluteus, which has been documented in China, is provided.