From a distance, the teddy bear cholla cactus (Cylindropuntia bigelovii) looks soft and welcoming with its fuzzy outstretched branches.
Looking closer, the "fur" on its branches is a dense covering of prickly spines. And, each spine is covered with numerous microscopic downward pointing barbs! Check out W.P. Armstrong's (350x) image of a cholla cactus spine. At the link, scroll down to the black and white scanning electron microscope picture to see why he calls this cactus "The Undisputed Most Painful Hitchhiker."
Several varieties of cholla (pronounced CHOY-ah) cacti grow in the Sonoran Desert, but the teddy bears are the thorniest. Cholla cacti grow to stand about five feet tall with central trunks like little trees.
Short branches easily detach and fall to ground, where they often root and grow forming a thicket of clones. Teddy bear cactus is often referred to as "jumping" cholla because the branches can suddenly fasten themselves onto fur, skin or clothing that lightly brushes against them. The cactus uses this hitchhiker strategy so that new plants will grow farther away from the parent plant and won't be competing for resources.
In addition to teddy bears, chainfruit chollas (C. fulgida) pictured below are also called jumping chollas. They grow and reproduce similarly to teddy bear chollas, but have fewer needles.
Recently when we were walking at Sabino Canyon, a teddy bear cholla became attached to Chris. He was not aware of getting that close to any cacti. A painful tugging at his leg felt like an animal was biting him.
The piece of cholla was stapling Chris' pants to his calf with its long sharp spines. He tried to remove the cactus with his fingers, but the needles were stuck. I tried flicking it away with a piece of wood, but the cholla ball just rolled to stick in a new spot on his leg.
A pair of pliers would've helped, if only we had brought them. With both hands, he tried yanking the fabric of his pants away from his leg.
It worked; he was free of the cactus! The pain was intense, but brief.
With their needles glistening in the sunlight, teddy bear chollas certainly help to make the Sonoran Desert look warm and inviting. Just be aware that these teddy bear characters are ready to hitch a free ride.
Visit more desert related blogs at Carnival of the Arid.