Taxonomic studies of bluish (Mycenaceae, Agaricales) with two new species from northern China.

Bluish are rare, but constitute a taxonomically complex group. A total of eight bluish species in four sections have previously been reported from North America, Europe, Oceania and Asia. Two species with a blue pileus, collected in China during our taxonomic study of s.l., are described here as new to science: and Detailed descriptions, line drawings and a morphological comparison with closely-related species, especially herbarium specimens of from the USA, are provided. The results of Bayesian Inference and Maximum Likelihood phylogenetic analyses of a dataset of 96 nuclear rDNA ITS and 20 nLSU sequences of 43 species are also presented. The morphological data and the results of the phylogenetic analyses support the introduction of and as new species. A taxonomic key to bluish species of sections , , and is provided.