Six new species and two varieties of Cuphea P. Browne (Lythraceae) are described from Brazilian collections. Cuphea lucens T. B. Cavalcanti & S. A. Graham from Minas Gerais is described in sect. Melvilla Koehne subsect. Pachycalyx Koehne where it is similar to C. cylindracea S. A. Graham but lacks the prominently descending floral tube spur of that species. Cuphea alatosperma T. B. Cavalcanti & S. A. Graham from the Amazon, with inflated-winged seeds, and C. anamariae T. B. Cavalcanti & S. A. Graham, a novelty from white sands in Minas Gerais, belong to sect. Euandra Koehne subsections Platypterus Koehne and Hilariella Koehne, respectively. Cuphea exilis T. B. Cavalcanti & S. A. Graham, C. filiformis T. B. Cavalcanti & S. A. Graham, and C. rupestris T. B. Cavalcanti & S. A. Graham, new species with linear-lanceolate leaves and a woody xylopodium (not confirmed in C. exilis), are members of sect. Euandra subsect. Oidemation Koehne, as are the newly recognized variety C. spermacoce A. St.-Hilaire var. arguta T. B. Cavalcanti & S. A. Graham and the new combination C. spermacoce var. erectifolia (Koehne) T. B. Cavalcanti & S. A. Graham. Lectotypes are selected for C. erectifolia Koehne and two forms of the species. A key to the varieties of C. spermacoce is provided.