Sonoran Desert - Columnar cacti

This scene contains all three columnar cacti that occur in the United States. Senita (Lophocereus schottii) is on the left, organ pipe cactus (Stenocereus thurberi) in the middle, and saguaro (Carnegiea gigantea) on the right. Senita Basin, Organ Pipe Cactus National Monument, Arizona.