Pulchragaricus rhodophyllus gen. et sp. nov. (Callistosporiaceae, Agaricales) from Yunnan, China, Based on Morphological and Molecular Data

Callistosporiaceae is a recently established family within the suborder Tricholomatineae, encompassing tricholomatoid, collybioid or pleurotoid morphological forms. While most species of this family exhibit a saprotrophic lifestyle and have been predominantly documented in Europe and Americas, records from Asia remain comparatively sparse. In this study, Pulchragaricus rhodophyllus gen. et sp. nov., discovered in a Pinaceae and Fagaceae mixed forest in southwestern China, is described based on a comprehensive approach integrating both multigene phylogenetic analyses and morphological methods. A concatenated dataset comprising nuclear ribosomal DNA (ITS, LSU) and protein-coding genes (rpb2, tef1-α) provides robust statistical support for the placement of Pulchragaricus within Callistosporiaceae. Morphologically, this new taxon is characterized by a tomentose and yellowish-brown pileus, pink to pinkish lamellae, a solid and basally tapering stipe, broadly ellipsoid to ellipsoid basidiospores, sparse and subclavate cheilocystidia, and plentiful clamp connections. This discovery not only broadens the known diversity and distribution of the poorly documented Chinese Callistosporiaceae, but also offers a potential clue for understanding the evolutionary origins of the ectomycorrhizal symbiosis within the family.