Cactuses come heavily armed with spines so cleverly shaped that they are called “fish-hook,” “eagle’s claw,” and “horse crippler.” These spines serve a double purpose: By building a lattice work around the stem of a cactus they shade it from the sun, and in many cases they make the cactus too prickly for animals to eat. Some animals have learned to use cactus spines for their own protection. The big, ratchet-voiced cactus wren likes to build its nest in the densely spined cholla, and the packrat often piles pricklypear pads in its nest area. Pricklypear is the commonest cactus in the park and also the easiest to identify. Purple-tinged pricklypear is just what its name suggests, and so is the brown-spine pricklypear. Blind pricklypear looks as if it has no thorns, but if you touch one of the velvety buttons on a pad, you will pick up a fingerful of almost invisible, but highly irritating little spines. Engelmann pricklypear is the most abundant species. And to human taste its fruits are delicious, although the tiny glochids, barbed spines, can hurt the mouth. Many desert creatures eat pricklypear: Flies, bees, and butterflies come to feast at the showy blossoms; birds, coyotes, peccaries, and deer eat the reddish fruits; small rodents reach between the spines to nibble on the juicy pads. In times of drought ranchers burn off the spines and feed the pads to cattle. And people lost in the desert can do as the Indians did—peel, cut, or roast the skin off the pads and the flesh yields both food and moisture. Some pricklypears are too bitter to eat, however. Cactuses [Illustration: Fish-hook cactus] [Illustration: Button cactus] [Illustration: Strawberry pitaya] [Illustration: Claret cup] [Illustration: Cholla] [Illustration: Pricklypear] [Illustration: Eagle’s claw] [Illustration: Rainbow cactus] [Illustration: Coarse strong fibers of the lechuguilla plant (top) were extracted by machine (bottom) for use in matting, ropes, bags, and household items.] [Illustration: Machinery] [Illustration: The candelilla or wax plant (middle) has been used in manufacturing waxes, polishes, chewing gum, phonograph records, and candles. In the rainy season the stem fills with milky sap. In the dry season this sap coats the stem as wax by evaporation. The wax protects the plant from drought.] One of the most interesting plants in the Chihuahuan Desert is a sturdy bunch of blades called lechuguilla. This fiercely spined agave lives nowhere else in the world. When Cabeza de Vaca crossed Big Bend in 1535, the lechuguilla grew so thick that he didn’t dare walk at night. Today you find it growing singly or in colonies from the shrub desert clear up into the Chisos woodlands, its needle points still menacing hikers, horses, and deer.