Subspecies, varieties, forms and cultivars of plants belonging to the Ferocactus echidne group

• Ferocactus echidne (DC.) Britton & Rose: (v. echidne) It has flattened globose stems and central spines less than 4.5 cm long. Distibution: It is widespread throughout the range of the species.
• Ferocactus echidne f. monstruosus hort.: It forms large low clusters of firm, rubbery-textured green tangled, monstrous stems. This cultivar shows many growing variations, with different crested, monstrous and normal shapes.
• Ferocactus echidne var. rafaelensis (J.A.Purpus): Stem flattened, globular, bluish, the flowers at first yellow-orangish take red-violet tones as they age (Same as: E. echidne v. rhodanthus?) Distribution. Minas de San Rafael, Sierra de Alvarez, San Luis Potosí
• Ferocactus echidne var. rhodanthus G.Unger: Stem ribbed up to 15 cm tall and 9 cm in diameter and central spine up to 6 cm long. Petals orange to brik-red with darker red-violed midribs. Distribution: Hidalgo (Barranca de Tolantongo, Barranca Xilitla), San Luis Potosi ( Ciudad del Maiz)
• Ferocactus echidne var. victoriensis (Rose) G.E.Linds.: This variety has more cylindrical stems with longer central spines (usully more than 4.5 cm long). Distribution: It is found Near Ciudad Victoria, Tamaulipas.