Smithiomyces umbonatus (Agaricaceae), a new species from Anhui Province, subtropical China

Smithiomyces Singer is a rare genus in the family Agaricaceae, previously known from the Neotropics and tropical Asia. Based on morphological observation and phylogenetic analyses of four nuclear loci (ITS, LSU, rpb2, and tef1-α), we describe Smithiomyces umbonatus sp. nov. from Anhui Province, China. The new species is characterized by a slightly prominent pileal umbo, conspicuous white rhizomorphs at the stipe base, and both 2- and 4-spored basidia. A full morphological description, field photographs, and line drawings of the microcharacters are provided.