Sistotrema subconfluens sp. nov. (Cantharellales, Basidiomycota) from Changbaishan Nature Reserve, northeastern China

Abstract Sistotrema , typified by S. confluens , is characterized mainly by its urniform basidia mostly with 6–8 sterigmata as well as by a monomitic hyphal system, oil rich hyphae and smooth basidiospores. The species of this genus have various hymenophore configurations and basidiospore shapes. During a field trip in 2011, two specimens with urniform basidia were collected from Changbaishan Nature Reserve, northeastern China. After careful morphological and molecular studies, they are described and illustrated here as a new species, S. subconfluens. The new species shares a terrestrial habit, stipitate basidiocarps and poroid hymenophores with S. confluens , besides urniform basidia. These characters make the two species different from all other species of Sistotrema with resupinate basidiocarps on wood. Sistotrema subconfluens differs from the type by having larger basidiocarps, shorter basidiospores and consistent poroid hymenophores. In phylogeny inferred from nuclear large subunit rDNA, the two species were sister taxa but clearly separated. The difference of internal transcribed spacer sequences between the two species was 3.6%.