Three new species of Calocybe (Agaricales, Basidiomycota) from northeastern China are supported by morphological and molecular data

Three new species, Calocybe aurantiaca, C. convexa, and C. decolorata, are described based on collections made in Shenyang City, Liaoning Province, China. The main characters of C. aurantiaca are its orange-yellow sporocarps and small and smooth basidiospores. Calocybe convexa is characterized by its orange-buff pileus, very small basidiospores, and tortuous stipe, whereas C. decolorata is mainly characterized by its gills that turn blue when bruised. The sequences of nuc rDNA ITS1-5.8S-ITS2 (ITS) and the 28S D1-D5 region of the Calocybe species were analyzed, and the results indicated that the three new species belonged to the genus Calocybe and differed from other species of Calocybe. The morphological similarities of the new species to other Calocybe species and the classification system within the genus Calocybe based on molecular data are also discussed. A key is provided for the Calocybe species as reported from China in order to facilitate future studies of the genus.