When you see a group of them at a distance in the "Cholla Cactus Garden" (Joshua Tree National Park), they're a memorable site. With their arms outstretched, these cacti seem rather fuzzy, almost soft, and hence the name "teddy bear". But don't let that fool you. They're evil, if a plant can be evil, as their other common name, "jumping cholla" implies.
The closer you get the more you realize that what looks like a soft fuzzy cover is actually a thick layer of firm, barbed, silvery spines. If you're skin is unlucky enough to come into contact with these spines, you'll find part of the plant painfully stuck to you. Segments almost seem to "jump" from the cholla and attach to your leg. The needles are barbed, like a fishhook, and very difficult to get off. Witness the suffering of this poor chap, who accidentally tried to "kick" off a cholla segment from his shoe (the exact same thing happened to my mother years ago in the same place):
The jumping cholla can be 3 to 7 feet (1 to 2 m) tall. It blooms in the spring, although it tends to propogate by direct spread and having animals take parts of a cholla with it. Jumping chollas grow on the valley floors of the Sonoran Desert and Mohave Desert at at 100 to 2,000 feet (30 to 600 m).
Despite their prickly personality, their hollow "wooden" skeleton is really lovely.