Gymnocalycium gibbosum

Succulent cactus with sub-globose stem. Stem with a diameter of about 5 cm but up to 12 cm with age, dark green-grey in color with large tubercles equipped with robust but short spines. White flowers with a diameter of about 6 cm. This species is widely distributed in the mountains of Argentina from the south of the province of Buenos Aires to Patagonia and shows great variability in morphological traits. The species grows in nature on sandy or gravelly alluvial soils along the Río Negro and the Río Colorado, under bushes and other mountain plants and in the Patagonian steppe, from 0 to 1,000 meters above sea level. It therefore requires very well-drained soil and a position in partial shade. Water once every 10-15 days in summer but leave dry in winter. Hardy.