Grusonia cacti are a type of cholla (cylindropuntia), characterized by short, club-shaped stem segments with pronounced tubercles bearing especially strong, sharp, dense spines, usually flattened and tapered. They form low mats, often covering a wide area, and are all quite similar in appearance, but each species tends to occur in a distinct geographical region. The plants are known collectively as club cholla due to their stem shape, or devil cholla because of the fierce spines.


There are two other US species:

Grusonia pulchella, sagebrush cholla, most of Nevada plus part of northwest Utah
Grusonia schottii, common dog cholla, west and south Texas, close to the Rio Grande