UC Berkeley

Species of the genus Macrolepiota (Agaricaceae) in China were investigated on the basis of morphology and DNA sequences data. Six species, i.e., M. detersa, M. dolichaula, M. mastoidea, M. orientiexcoriata, M. procera, and M. velosa are recognized, of which M. detersa and M. orientiexcoriata are new species. All of them are described and illustrated with line drawings, and a key is provided to those recognized species. The taxonomic uncertainty of M. crustosa, originally described from China, is also discussed. ITS sequences were used to support the new species delimitations and to test the conspecificity between the Chinese specimens and their relatives from other continents. Phylogenetic analyses identify three clades within Macrolepiota: /macrolepiota, /macrosporae, and /volvatae clade. /macrolepiota clade and /macrosporae clade respectively correspond to section Macrolepiota and section Macrosporae in Bon’s infrageneric classification. Section Volvatae is proposed to accommodate species with a volva but without clamp connections within Macrolepiota.