Ferocactus wislizeni

Common Name: Compass Barrel Cactus
Oˊodham Name: Jiawul Audio
Group: Cacti － Desert

Description

Ferocactus wislizeni is the large barrel cactus found in the deserts east of Sells, Arizona and in the southern 1/3 of the state. This species grows in sandy and gravelly soils from 1500 ft to almost 4500 ft in sheltered locations. Flower buds are produced in August and open in concentric rings, working from the outside inward. Flowers may be yellow, salmon, orange, or red, and range in size from about 2-1/2 to 4 inches in diameter. The flowers produce rings of 2 inch long green fruit which turn yellow as they ripen. Each fruit contains around 1000 seeds packed in a thick. sticky mucilage. These fruit contain a large amount of oxalic axis which gives them a bitter taste and can cause sickness if eaten. Fruit are water tight and persist on the plant until the following Spring to provide a rich food source for desert birds, rodents, rabbits, and javelinas. Uneaten fruit often end up as food for desert ants.

The common name "Compass Barrel" comes from its habit of leaning southward to point directly south and angled into sun as a way of minimizing sun exposure. Eventually, the plant becomes sufficiently large and heavy that this imbalance cannot be supported by the roots and it uproots itself to fall flat on the ground. If enough roots remain intact in the ground, the plant continues growing and angles its growing tip upward toward the sun; otherwise, it dies.

entire plant
fruit (August)
fruit
hooked spines
ring of flowers
flower
Ring of flower buds

Nectaries