Taxonomic studies on Hygrophorus in China: New species and revised taxonomy

A taxonomic revision of the genus Hygrophorus in China was conducted using integrated morphological and molecular phylogenetic analyses, based on sequences of the internal transcribed spacer (ITS) region, the large subunit nuclear ribosomal RNA (nrLSU) and the translation elongation factor 1 - alpha (tef 1 - α) gene. Our study confirms the recognition of five new species as H. atropurpureus and H. ochraceodiscus in sect.

Hygrophorus; H. paulus and H. shennongjiaensis in sect. Pudorini; and H. aurantiophyllus in sect. Vividi.

Phylogenetic analysis, based on ITS data and the concatenated ITS + nrLSU + tef 1 - α dataset, demonstrated that H. atropurpureus groups with H. aff. atropurpureus; H. ochraceodiscus is sister to H. brunneodiscus; H. aurantiophyllus forms a clade with H. vividus and an undescribed taxon; and H. paulus and H. shennongjiaensis group together with H. nemoreus. Detailed morphological descriptions, ecological notes and updated geographical distribution records are provided for these new taxa as well as for several previously described species.

These findings bring the total number of confirmed Hygrophorus taxa in China to 63, establishing a more robust framework for understanding the diversity of this genus in the region.