A new system of classification and phylogeny of three subtribes of Cacteae is briefly outlined. On the basis of new available data on seed morphology and anatomy of the tribe, published recently (Doweld, 1995), supplementing other available data on spine and areole morphology, flower and fruit structure, it has been proposed 12 subtribes in Cacteae instead of 4 in the system of F. Buxbaum (1958): Sclerocactinae, Astrophytinae, Epitheianthinae, Echinocactinae, Bravocactinae, Turbinicarpinae. Pediocactinae, Thelocactinae, Coryphanthinae, Neobesseyinae, Escolloydinae and Cactinae.

Three new subtribes were created and validated in the present review: Sclerocactinae, being the most archaic within the whole tribe, and its derivatives: Bravocactinae and Turbinicarpinae. Sclerocactinae are treated as comprising 5 distinct genera: most archaic Emorycactus and its two closest allies, Homalocephala and Toumeya, and somewhat distanced two distinct genera Sclerocactus and Echinomastus. Bravocactinae represent an early diverged, highly specialized phylum comprising three new genera; monotypic Torreycactus (based on Thelocactus conothele, an aberrant species in Thelocactus, which is distinct in spination, areole structure, seed and articular morphology), monotypic Bravocactus (based on Mammillaria horripila = Gymnocactus horripilus, a doubtful species of Gymnocactus, differing in seed and cuticular sculpturing, spination and areole structure), and again monotypic Kadenicarpus (accommodated only Turbinicarpus pseudomacrochele, an aberrant southern element in Turbinicarpus].

Bravocactinae are treated as a connecting link between the more primitive Scterocactinae and highly specialized Turbinicarpinae. The other highly advanced descendant, Turbinicarpinae, is represented by 8 genera only, having papillate seed sculpturing and striate cuticular sculpturing: Hamatocactus, Turbinicarpus, Geohintonia, Aztekium, Gymnocactus, Ariocarpus, and Strombocactus. The review and validization of other subtribes would be published elsewhere. 10 new taxonomic combinations were made to modify the taxonomy of the tribe Cacteae.