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Ferocactus diguetii
Barrel Cactus, Biznaga

CACTACEAE (Cactus Family)

The generic name refers to the ancient Greek ferox meaning very spiny. The specific epithet honors Leon Diguet, a French explorer who was investigating pearl fisheries on Santa Catalina Island in the Gulf of California.

Description

This barrel cactus is the largest of all of the genus Ferocactus; it reaches 4 m (12 feet) tall and may grow almost 1 m (3 feet) in diameter. The fiery red to orange flowers bloom from March to May.

Range and Habitat

Ferocactus diguetii is a Gulf Island endemic, found only on Carmen, Catalina, Cerralvo, Danzante, and San Diego islands. This cactus is an example of the phenomenon of gigantism, well known in island biology. It is quite common for the species found on islands—both plants and animals—to be larger and more robust than their nearest relatives on the mainland. The largest individuals of this species occur on Santa Catalina Island, also home of the famous endemic rattleless rattlesnake.

Natural History

Photo of Ferocactus diguetii (Barrel Cactus), with Professor William C. Steeve in 1952, by Reid Moran © 2000 SDNHM This cactus demonstrates the ribbed columnar structure that is an important adaptation for tall cacti growing in areas of uncertain rainfall. Water is stored within the tissues of the trunk during times of abundance, and as the trunk swells to hold it, the ribs flatten out. As water is used during later dry times, the pleating of the ribs allows the size of the column shrink, while still providing structural strength for the tall trunk.

A common cause of disaster for barrel cacti is that they often grow at a slight angle, and when their column fills with water, they become top-heavy and fall over.

Photo of trunk of Ferocactus diguetii (Barrel Cactus), Catalina Island, by Reid Moran © 2000 SDNHM Photo of flowers of Ferocactus diguetii (Barrel Cactus), Catalina Island, by Reid Moran © 2000 SDNHM

Text by Bob Lauri
Photographs by Reid Moran. Left photo of Barrel Cactus with Professor William C. Steere, taken in 1952.

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