A new species and new records species of Pluteus from Xinjiang Uygur Autonomous Region, China

Xinjiang Uyghur Autonomous Region in China embraces a unique geographical and ecological environment, and the macrofungi represent a rich resource. However, few studies on the genus Pluteus have been reported from Xinjiang. In 2021, the macrofungal resources in Xinjiang were surveyed, and 10 specimens belonging to the genus Pluteus were collected. Based on the morphological study and molecular analysis, three species were recognized, P. aletaiensis, P. brunneidiscus, and P. hongoi. Pluteus aletaiensis is proposed as a new species. It is characterized by its bright yellow lamellae and stipe, brittle texture, subfusiform to vesicular pleurocystidia, with short pedicels to broadly lageniform to obtuse at apices, a hymeniderm pileipellis, containing dark brown intracellular pigment, and it grows on the ground. Pluteus brunneidiscus, a new record to China, is characterized by uneven, smooth, grayish brown to brown pileus, with an entire margin, and pointed or flatter apices intermediate cystidia, without apical hooks. Pluteus hongoi, a new record to Xinjiang Uyghur Autonomous Region, China, is characterized by the apical hook's structure (commonly bifid) of pleurocystidia. The nuclear internal transcribed spacer (nrITS) and translation elongation factor 1-alpha (TEF1-a) region were used for the molecular analysis. Phylogenetic trees were constructed using both the maximum likelihood analysis (ML) and Bayesian inference (BI). Detailed descriptions of the three species are presented herein. Finally, a key to the list of eight species of the genus Pluteus knew from Xinjiang is provided.