Gymnocalycium uebelmannianum is a cactus species that begins as a solitary plant and later forms clusters.

The cactus features 8 to 12 (occasionally up to 18) ribs, which are divided into chin-like humps by transverse notches between the areoles.

The five to seven chalky white radial spines are flexible, curved, often twisted, and range from 0.5 to 1.5 cm long, with one pointing downward.

The flowers are broad, funnel-shaped, and white with a light pink throat, measuring up to 3.5 cm in both length and diameter.

[2] This species is native to the Sierra de Velasco in La Rioja, Argentina, where it grows at elevations of 2200 to 2800 meters.