Abstract
Russula rubrosquamosa (Russulaceae, Russlales) is described as a novel species from Yunnan Province, southwestern China. It is morphologically recognised by a small basidiocarp with orange-yellow to orange-red scales on the pileus and stipe, white lamellae, orange-red to bright red basal mycelia, subglobose to broadly ellipsoid basidiospores with dense warts and short or long ridges. Phylogenetically analyses of DNA sequences from part of the 28S gene combined with the nuclear rDNA internal transcribed spacer (ITS) region also confirm that R. rubrosquamosa forms an independent lineage within Russula subgenus Heterophyllidia section Ingratae. A comprehensive description, color photographs of fresh basidiomata, line-drawings of microstructures and comparisons with morphologically similar species are provided in this paper.