The saguaro cactus (carnegiea gigantea) is the largest cactus species in the United States and is a defining image of the Sonoran Desert. As an international icon of the American Southwest, the saguaro’s unmistakable silhouette is often used for commercials and brands that want to convey the idea of the wild west. Growing about an inch a year, the height of a saguaro is between 15-50’ (4.5 m - 18 m) with an average height of 30’ (9 m). The tallest recorded saguaro cactus was 78’ (23.8 m).
Tree-like, the saguaro cactus grows arms as it ages over 150-200 years and may grow upwards of 25 arms over its lifetime. Not in any rush, the first arm may take 75-100 years to grow and will continue to grow more to assist in reproduction—as each arm increases the opportunity for more flowers and fruit. Some saguaro cacti never grow arms and remain ‘spears.’ The saguaro cactus has a great capacity to store rainwater and will visibly expand during wet periods in order to survive future droughts.