The desert seems to be a brown wasteland of dry, prickly scrub whose only purpose is to serve as a setting for the majestic saguaros. Then, little by little, the plants of the desert begin to identify themselves: the porcupiny yucca, the beaver tail and prickly pear and barrel cacti, buckhorn and staghorn and devil's fingers, the tall, sky-reaching tendrils of the ocotillo.