World's Largest Cactus

The world's largest cactus species is the Saguaro cactus. Pronounced "sah-wah-roh", it is native to the Sonoran Desert of southern Arizona, southeastern California, and northwestern Mexico.
The plant grows very slowly and can take up to 75 years to grow a second arm. The largest and oldest Saguaro have been estimated at nearly 200 years old and can reach heights of 40 or more feet (12 meters). However, the average old Saguaro has approximately five arms and is about 30 feet (9 m) tall.