The saguaro cactus, Carnegiea gigantea, only grows in the Sonoran Desert, but not in all parts. Saguaros need a perfect balance of heat and rainfall to thrive. Freezing temperatures can be greatly detrimental to the health of a saguaro, and climate is the main determinate of saguaro range. Thus, they are limited to a specific area within the Sonoran Desert, ranging mostly from central Arizona down into Sonora, Mexico.
