Cylindropuntia bigelovii

The teddy-bear cholla, Cylindropuntia bigelovii, is a cholla cactus native to northwestern Mexico and to California, Arizona and Nevada in the United States. It stands about 0.3 to 1.5 metres tall with a distinct trunk that darkens with age and nearly horizontal branches at the top. Silvery-white spines about 2.5 centimetres long, each under a detachable paper-like sheath, cover the stems so densely that the plant looks soft, which earned it the sardonic nickname teddy bear. Yellow-green flowers open at the stem tips in May and June, but the fruit holds few if any viable seeds, so the plant mostly spreads by dropped or animal-carried stem pieces that root, and small stands are often clones of one individual. It grows in desert regions up to about 900 metres in the Colorado Desert and other parts of the Sonoran Desert, and desert pack rats pile its detached stem joints around their burrows as protection from predators.