Cylindropuntia fulgida, the jumping cholla, also known as the hanging chain cholla, is a cholla cactus native to the Southwestern United States and Sonora. Cholla is a term applied to various shrubby cacti of this genus with cylindrical stems composed of segmented joints.
These stems are actually modified branches that serve several functions
-- water storage, photosynthesis and flower production.The structure of cacti enables them to survive in hot, dry climates.
Most have thick, fleshy stems with a waxy skin surface. The stem acts
as a reservoir to store water. The tough skin keeps the water from evaporating.
In addition, surfaces of most cacti can expand and contract to accommodate
changes in the amount of water.