A revision of the African Russula radicans and allies in subgen. Heterophyllidiae provides an example of a clade that exhibits recent diversification and extensive phenotypic plasticity.
Russula subsection Radicantinae is described for R. radicans and allies, while subsection Aureotactinae is again restricted to R. aureotacta, the subsectional type species that has never been recollected since its original description. Russula radicans, originally described from Madagascar, as well as the Central African R. brunneoannulata, are epitypified. Russula xylophila is the first confirmed annulate species belonging to Sect. Ingratae and a close relative to R. oleifera. An ITS sequence has been obtained from the R. xylophila holotype collection made in 1928, but it is slightly different from those obtained from all new collections. For this reason and some minor morphological differences, we refrained from epitypification. Russula acriannulata, another species attributed to Aureotactinae in the past, is now also excluded from the subsection, but needs more sequencing to solve its systematic placement. The Malagasy Russula cibaensis and R. tapiae, as well as the Central African R. cameroonensis and R. afrovinacea are new species in Radicantinae.At least three more undescribed species are revealed by environmental sequences. The West African R. sankarae is reduced to a form of R. radicans. The latter species exhibits an impressive phenotypic plasticity in response to differences in habitat or host associations. It has a very wide distribution covering littoral rain forest in eastern Madagascar (forma radicans), Zambezian woodlands in Central and Eastern Africa (forma miomboensis fo. nov.) and gallery forests in West Africa (forma sankarae).