Subspecies, varieties, forms and cultivars of plants belonging to the Echinocactus horizonthalonius group

• Echinocactus horizonthalonius Lem.: It is a relatively small barrel cactus that normally grows unbranched. The body of this plant is a chalky blue colour, and some forms have magnificent spines.
• Echinocactus horizonthalonius var. minimus: even very small plants are able to flower. Distribution: Cedral towards Esacion Vanegas, San Luis Potosi, Mexico.
• Echinocactus horizonthalonius f. montruosa hort.
• Echinocactus horizonthalonius subs. nicholii (L.D.Benson) Doweld: Stem eight- ribbed, pale grey-green to bright blue-green, up to 50 cm tall and 20 cm across. Distribution: Sierra del Viejo, Sonora (Mexico) and Pinal County, Arizona (USA).
• Echinocactus horizonthalonius var. subikii Stanik & Dráb: is a rare, very stunted, bluish frosted and pure white Flowering form. Distribution: Ejido Soledad, Nuevo León, Mexico
• Echinocactus horizonthalonius cv. Albinous (Yellow form) hort.: ( Chlorophylless form) Stem with a bright yellow overall appearance and grey/red contrasting spines.
• Echinocactus horizonthalonius cv. Sirotoge Suiheimaru hort.: Short spined mutant selected in Japan.