Phylogeny and species diversity in Hygrophorus section Aurei in China

The relationships among species of Hygrophorus sect. Aurei were inferred based on morphology, molecular phylogeny, and chemical reactions. It was found that (1) there are at least 14 species within the section, seven of which occur in China. Among the Chinese taxa, four are new, viz. , H. alpinus , H. esculentus , H. pseudohypothejus , and H. xiangjun . They were collected in the subalpine and alpine areas of southwestern China. The occurrence of H. gliocyclus , H. lucorum , and H. speciosus in China was confirmed based on molecular and morphological evidences. (2) Geographic divergences of this section in the Northern Hemisphere were evident. Four taxa were intercontinental, viz ., two Eurasian species ( H. gliocyclus and H. lucorum ), one European-North American species ( H. secretanii ), and one Holarctic species ( H. speciosus ). (3) Most species in this section display relatively high host preferences for their host plants at the generic and even subgeneric level.