Plant Fact Sheet

Cactaceae
California Compass
Barrel Cactus
Ferocactus cylindraceous

California Barrel cactus grows in a rounded, globular shape when young, then in age it grows taller in a cylindrical or columnar shape that can reach nearly 10 feet in height in older specimens. Because barrel cacti do not make growth rings, like many trees, it is difficult to know the age of a specimen growing in natural habitat. The stems are very spiny and can be comprised of as many a 27 ribs. At the top of the cactus, the areoles, or the spots where spines emerge, are covered with a felt-like mass of hairs when young, and the actively growing spines can be white, pink, or bright red. The flowers that form near the top of the cactus are yellowish, bloom in spring, and are somewhat dependent on winter and spring rains. California barrel cactus plants have a noticeable lean to the south—the direction of solar radiation. It is speculated that because the stem cells on the north side of the cactus are shielded from the direct sunrays, they grow relatively longer than the stem cells on the south side, giving the plant this tilt to the south. This characteristic lean to the southwest is how the common name, Compass Barrel, is derived.

Barrel cacti are well adapted to non-motile life in the desert. Their succulent structure and photosynthetic method allow these cacti to be highly efficient at water storage. Their shallow root system allows for rapid uptake of water after rain. The structure of the body, or stem can swell to accommodate increased amounts of water storage, and shrink in times of drought. They generally open their tiny pores, or stomata, only at night to take in carbon dioxide, which reduces evaporation. It is believed that their spines help to deflect sunlight from excessively heating the skin of the cactus, and to avoid possible sunburn—remember they can’t simply get up and find a shady spot.

California barrel prefers gravelly hillsides, rocky slopes, canyon walls, alluvial fans, and wash margins in desert areas from 200 to 2,000 feet in elevation. They are found naturally in Arizona, southwestern Utah, The deserts of southeastern California, and northern Baja California.

In California and Arizona, it is illegal to remove a barrel cactus from nature without the proper native plant permit. These native plant permits are usually only given when a cactus is in danger due to development or construction activities. In this case, the native plant permit tag must accompany the cactus plant. Plants that have been salvaged or moved may not be sold without the permit. These cacti can be purchased at local nurseries, especially cactus nurseries, but should not be purchased if the proper permit is lacking.