Gymnocalycium eurypleurum grows in dry forest where many groves shed their leaves during Winter (June-September). The majority of plants consist of up to 6 metre high, almost impenetrable bushes. Everything pricks or stabs in some way. On the ground we find opuntias and different bromelias. The soil consists of clayey silt that is covered by loess and loess clay. Its exact composition varies depending on the habitat. Cultivation of humus rarely takes place. The soils are rich in nutrients, the pH-value is between 6,8 and 7,2. During dry periods the ground becomes "rock-hard". The yearly rainfall ranges between 500 and 800 mm. During winter, temperatures sink as low as 0°C, while rising up to 50°C during summer. G. eurypleurum's natural range is considerable bigger than hitherto known - I was able to locate the species in Paraguay, almost up to the border to Bolivia.