Subspecies, varieties, forms and cultivars of plants belonging to the Gymnocalycium spegazzinii group

• Gymnocalycium cardenasianum cv. Japanese Selection: has long, stout spines, eagle claw-shaped, typically-twisted, up to 4 cm long. Black turning dark grey as they ages. It has been selected in Japan.
• Gymnocalycium cardenasianum cv. Japanese Selection f. cristatum: is a beautiful crested form with stout black spines typically-twisted, eagle claw-shaped, up to 4 cm long. It has been selected in Japan.
• Gymnocalycium spegazzinii Britton & Rose: is a flattened solitary cactus with very characteristic spines pointing sideways or downward. Distribution: North Argentina on hight altitude and Bolivia.
• Gymnocalycium spegazzinii subs. armatum (F.Ritter) Halda & Šorma
• Gymnocalycium spegazzinii subs. cardenasianum (F.Ritter) R.Kiesling & D.Metzing: is densely covered with incredibly strong twisted spines up to 6cm long, pointing sidewards and downward. Usually whitish or pale brown. Distribution: Bolivia (Tarija and Chuquisaca).
• Gymnocalycium spegazzinii var. horizonthalonium Backeb.: is characterized by a variability in the length and shape of the spines and has received many names, leading to confusion with the entirely dissimilar Echinocactus horizonthalonius.
• Gymnocalycium spegazzinii var. major Backeb.
• Gymnocalycium spegazzinii var. punillense H.Till & W.Till: The spines are typically recurved, add-pressed against the body, pointing downward and most attractive. Distribution: La Punilla (Argentina, Prov. Salta, Rio de Los Conchas)
• Gymnocalycium spegazzinii subs. sarkae Halda & Milt: with different seeds, darker purple-brown epidermis and long spidery spines. Distribution: Argentina, Salta, San Felipe – La Angostura.
• Gymnocalycium spegazzinii var. unguispinum Slaba: has only 5 short spines less than 1 cm long, stout, subulate, eagle claw-shaped, typically-twisted and curved gracefully outward and downward. Distribution: South of Puerta Tastil, Salta, Argentina.