Abstract
The collections of Xanthoconium from tropical China are investigated on the basis of morphology and molecular phylogenetic analyses of DNA sequences from the nuc 28S rDNA D1-D2 domains (28S), the translation elongation factor 1-α gene (TEF1) and RNA polymerase II second largest subunit gene (RPB2). Two species are recognized in the region, one is the previously described taxon: X. sinensis, the other is described as new: X. fusciceps. Xanthoconium fusciceps is morphologically characterized by a dark brown pileus with a rugulose or pitted surface, non-staining hymenophore and context, golden yellow basidiospores, cystidia with pale yellowish brown, yellowish brown to golden brown pigments, and uninflated hyphae in the pileipellis. Detailed descriptions, color photos of fresh basidiomata and line-drawings of microstructures of the two taxa are presented.