New Contributions to the Species Diversity of the Genus Hydnum (Hydnaceae, Cantharellales) in China: Four New Taxa and Newly Recorded Species.

Hydnum, a well-defined genus in the family Hydnaceae (order Cantharellales), is characterized by its distinctive spine-bearing hymenophores. In this study, we performed a multi-locus phylogenetic analysis (ITS-nrLSU-tef1) of Hydnum species. Integrating morphological examinations and phylogenetic evidence, we identified and delineated five Hydnum species in China, which include four novel species (Hydnum crassipedum, H. albomarginatum, H. fulvostriatum, and H. bifurcatum) and the first record (H. orientalbidum) in Anhui Province. This study provides a comprehensive morphological description (including macroscopic morphology and microscopic structure), hand-drawn illustrations (encompassing basidiocarps, basidiospores, basidia, and pileipellis hyphae), morphological comparative analysis with similar species, and comparative phylogenetic analysis with related taxa. Furthermore, we developed a dichotomous key for identifying Hydnum species distributed in China.