Genus Carnegiea is a type of cactus that is native to the American Southwest. It is also known by other names such as saguaro cactus, Carnegiea gigantea, or simply saguaro. The saguaro cactus is one of the most recognizable symbols of the American Southwest. It has a tall, columnar shape, and can grow up to 50 feet tall. It is also known for its distinctive arms, which are actually large branches that form after the plant is around 75 years old. Other synonyms for Genus Carnegiea include Pilocereus giganteus, Cereus giganteus, and Lophocereus schottii.