Four new species in Leucoagaricus (Agaricaceae, Basidiomycota) from Asia.

The genus Leucoagaricus has been well studied in Europe. However, species diversity of Leucoagaricus in Asia remains poorly known, especially in the mountains of southwestern China, a hot spot for biodiversity. Based on morphological characters and molecular data, four new species are described, La. asiaticus, La. subcrystallifer, La. subpurpureolilacinus and La. truncatus. Detailed morphological descriptions, drawings of microstructures for novel taxa and comparisons with closely allied taxa are provided. Phylogenetic analyses inferred from internal transcribed spacer (ITS) and region 6-7 of the gene for the second largest subunit of RNA polymerase II (rpb2) sequences show that the novel taxa are nested within a well-supported clade jointly formed by members of Leucoagaricus section Rubrotincti and subgenus Sericeomyces.