This paper presents a taxonomic treatment of the exclusively North American subsection Crassotunicatinae of Russula sect. Ingratae. There follow descriptions and discussions of North American material of 16 additional species from various sections of the genus: R. simillima, R. variata, R. aeruginea, R. galochroa, R. basifurcata, R. vesca, R. brunneola, R. peckii, R. purpureomaculata sp. nov., R. brunneoviolacea, R. krombholzii. nom. nov. (=R. stropurpurea (Kromb.) Britz. 1893 non Pk. 1888), R. fragilis, R. paludosa, R. velenovskyi, R. aurantiolutea, and R. adulterina.