Euphorbia is one of the largest of the succulent plant families. The genus Euphorbia is found throughout the tropics and semi tropics around the world, with some members of the family growing well into temperate regions.
From Mexico and Southern US. Usually having heavy spination and relatively small flowers, the fruits are copiously woolly. Includes the "Golden Barrel Cactus".
Most of these are from Mexico, although they occur in the southern United States and into South America.
Four related genera native to South Africa that grow in a Mediterranean like environment with winter-rainfall; similar to that of Southern California.
Epiphytic cacti do not live in soil like other cacti but in places like rain forests they inhabit the forks or large branches of trees, their roots clinging tightly to their host. Epiphytes have specially designed stomata (leaf openings), that help absorb moisture from the open air.