The Sonoran Desert stretches across Southern California, Arizona and adjoining portions of Mexico. It is within this desert that the iconic saguaro cactus grows. The most distinct of all the Southwestern cacti, saguaro produces the state flower of Arizona. This cactus is tall and columnar when it matures. An average saguaro stands 30 feet tall and has five thick arms that can measure up to 24 inches in diameter. The cactus is covered in 2-inch-long spines and flowers with cream-to-white flowers with yellow centers. Many of large saguaros are estimated to be more than 200 years old.
Also known as the old man cactus, the senita gets it nickname from the appearance of its spines. With short 3/4-inch spines near the base and spines up to 3 inches long near the top, the plant looks from a distance as if it has shaggy gray hair. It also is known as the whisker cactus for the same reason. This member of the cactus family grows in a clump as wide as 15 feet in diameter and stretches up to 21 feet in the air. Between April and August the senita blooms with pale pink flowers that open only at night. It is most common in Sonora, Mexico, and occasionally is found in Arizona.
The cardon cactus is native to San Felipe on the Baja peninsula. It is the world’s tallest cactus species. According to the Gardening Central website, cardons have been reported to live beyond 300 years of age while reaching a massive weight of 25 tons and 70 feet tall. The cardon braches from a base, having as many as 25 or more vertical branches that each can measure 5 feet around. These cacti easily store as much as a ton of water inside the plant pulp. They have a shallow root system that quickly sucks up any available water for storage.
The organ pipe cactus is a species that grows only in the Sonoran Desert within a small area of southwestern Arizona and western Sonora, Mexico. The cactus tends to only grow on south-facing slopes where it is very sunny and at elevations between 1,000 and 3,500 feet. The organ pipe grows from a wide base with many columns that can reach as high as 23 feet. It is the second-tallest cactus in the United States.