There is nothing so universally associated with the desert Southwest than the saguaro cactus. Here is a clip art design of the cactus for comparison with the real live cactus:
Now, what is the reality? Saguaro cactus or Carnegiea gigantea are only native to a small portion of the desert Southwest. They are generally confined by temperature zone to those areas of the state below 4000 feet and then only to areas where there is enough rainfall. For example, there are very few saguaro cactus in southern Arizona especially near Yuma in the southwest corner of the state. The cactus are also found in the Mexican state of Sonora, in a very small part of Mexican state of Baja California Norte, and in an extremely small area in the extreme east of California along the Colorado River.