It develops 7–12 ribs (rarely 5), divided by furrows with small chins beneath each bump.

Its white, dioecious flowers feature a pale purple-pink throat, are up to 6 cm long and wide, and have green to olive-green pericarpels with scales tinged reddish at the tips.

The green, pear-shaped fruits soften when ripe, containing oval seeds that are brown to black and 1–1.6 mm long.

[3] Native to Paraguay, it is found in Paraguarí, Cordillera, and the Chaco region at altitudes of 150 to 300 meters in partial shade.

[4] Discovered as Echinocactus paraguayensis by Karl Schumann in 1903, it was reclassified to Gymnocalycium by Carl Hosseus in 1939.