Difference Between Barrel Cactus and Saguaro Cactus

Geography

• The saguaro cactus grows native in much of the Sonoran Desert, which is in parts of Arizona, California and northern Mexico. The northern distribution of this species is in Arizona's Hualapait Mountains and to the Colorado River in southeast California. Barrel cactus grows wild in southeastern Arizona counties such as Cochise and Lincoln County in the southwestern corner of the state. The range extends eastward to southern portions of New Mexico and to extreme western Texas.

Size and Form

• The most obvious difference between these cacti species is in their size and shape. A barrel cactus averages between 24 and 60 inches high, with the biggest specimens growing to around 10 feet. Widths vary between 12 and 33 inches, giving the plant its classic barrel look. The saguaro grows much bigger, with some as gigantic as 53 feet. Their widths though are small compared to their height, with one as wide as 29 inches considered large. Saguaros typically feature one to five lateral branches growing erectly from the main trunk. Barrel cacti lack such branches.

Flowers and Fruits

• The flowers of the barrel cactus are a brilliant orange and grow in a circular pattern at the top of the plant. The fruit resembles a small yellow pineapple, with the fleshy fruit edible by wildlife and up to 2 inches in length. The white flowers of the saguaro develop on the top of the trunk and at the ends of whatever branches occur on the plant. They yield an oval, red spiny fruit as long as 4 inches that is also edible.

More Differences

• The spines on a barrel cactus curve inward, giving the plant the nickname of fishhook cactus. Saguaro spines are straighter. The root system of a barrel cactus is relatively shallow, with a lateral system of roots branching out from the main one. Rainstorms can expose barrel cactus roots. The roots of the saguaro are much more extensive, with the taproot going down to depths of 3 feet and the branching, lateral roots extending as far as nearly 100 feet from the plant.