This taxon was originally described as a variety of R. emetica from northern Argentina where it was found under Alnus jorullensis (currently known as A. acuminata). Although we have not collected extensively in stands of A. acuminata in Costa Rica, L. D. Gómez and R. Alfaro (Rev. Biol. Trop. 44(suppl. 4): 25-38. 1996) list this Russula as occurring in Costa Rica.