The saguaro (/səˈwɑːroʊ/, Spanish pronunciation: [saˈɣwaɾo]) (Carnegiea gigantea) is an arborescent cactus species in the monotypic genus Carnegiea, which can grow to be over 40 feet (12 m) tall. It is native to the Sonoran Desert in Arizona, the Mexican State of Sonora, and the Whipple Mountains and Imperial County areas of California. The saguaro blossom is the state wildflower of Arizona. Its scientific name is given in honor of Andrew Carnegie. In 1994, Saguaro National Park, near Tucson, Arizona, was designated to help protect this species and its habitat.





Some saguaros are cristate or "crested" due to fasciation.




A house sparrow nesting on a saguaro cactus
Saguaros have a relatively long lifespan, often exceeding 150 years. They may grow their first side arm any time from 75–100 years of age, but some never grow any arms. Arms are developed to increase the plant's reproductive capacity, as more apices led to more flowers and fruit.

A saguaro is able to absorb and store considerable amounts of rainwater, visibly expanding in the process, while slowly using the stored water as needed. This characteristic enables the saguaro to survive during periods of drought. The saguaro cactus is a common image in Mexican culture and American Southwest films.