Habitat
an icon of the Sonoran desert. grows in large colonies.
Flowers
yellow-green flowers emerge at the tips of the stems
Description
an erect plant, standing 1-2 m (3-5 ft) tall with a distinct trunk. The branches are at the top of the trunk and are nearly horizontal. Lower branches typically fall off, and the trunk darkens with age. The silvery-white spines, which are actually a form of leaf, almost completely obscure the stem
Comments
an attractive plant, having a soft appearance due to its solid mass of very formidable spines that completely cover the stems. From a distance, the stems appear soft and fuzzy, giving it the name "Teddy bear".
stems of this cactus detach easily and the ground around a mature plant is often littered with scattered cholla balls and small plants starting where these balls have rooted. When a piece of this cholla sticks to an unsuspecting person, a good method to remove the cactus is with a hair comb. Nair is also helpful.

Primary Source: wikipedia.