Origin and Habitat: Cerro-Medina, 1000-1500 m, Tucumán (Argentina)

Habitat: The plants typically grow under the protection of grasses and shrubs.

• Gymnocalycium bayrianum H.Till
• Gymnocalycium spegazzinii var. bayrianum (H.Till) Halda

• Gymnocalycium bayrianum H.Till
• Gymnocalycium spegazzinii var. bayrianum (H.Till) Halda
• Gymnocalycium bayrianum var. brevispinum hort.

Description: Its distinctive feature is the strong curling spines which look like pairs of buffalo-horns. It is one of the best spined species.
Stem: Rather flat, approx 10 cm in diameter and 4-5 cm tall, light green to blue-green taking a brownish to cherry shade when exposed to strong sun light and under under stress conditions.
Ribs: 6-10, rather flat, tubercles distinct but rather shallow.
Root: Produces a long tap-root and thus requires a deep pot.
Areoles: With yellowish wool.
Spines: Strong 3-5, depending on the age, 3 cm long, curved, light brown.
Flowers: Attractive funnelform, creamy-white with a reddish throat, 6x4 cm.
Fruit: Long, grey-green.
Remarks: The var. “brevispinum”” is a catalog name used to distinguish a form with few shorter and strong spines.