Sclerocactus uncinatus (2012)

By Barbara Rengers (March 2012)

Sclerocactus uncinatus belongs to the Cactaceae family. Sclerocactus means “hard cactus,” from the Greek, referring to the hard, dry fruit. In Anderson’s book The Cactus Family, he says it means hard or cruel, referring to the hooked spines that “hold on in the most aggravating manner.” Trying to remove a hooked spine from a finger or clothing without doing damage to the plant does require patience.

There are approximately 15 Sclerocactus species, depending on the authority from which you are gleaning information. Researchers suggest that the genera Ancistrocactus, Echinomastus, Glandulicactus and Toumeya should all belong in Sclerocactus. This is still under debate, so label these plants as you wish.

My plant was purchased in 1999 and labeled Ancistrocactus uncinatus. It has been badly grown but is still alive – and is one of my favorites because it is native to the United States. Now that I’ve done a little more research into what the plant requires, I hope to purchase another and have much better results.

Common names for this genus of plants include fishhook cactus and little barrels. Most have at least one reddish, hooked spine coming from each areole.

S. uncinatus are bluish-green, solitary, cylindrical cacti up to 8 feet tall and 3 feet in diameter. The plants bloom in mid-summer, and the blooms are orange to maroon. They can be found on the Colorado Plateau, Mohave Desert or Great Basin – all higher-elevation deserts where they are exposed to extreme elements, little rainfall, hot summers and below-freezing winters.

The Endangered Species Act protects many Sclerocactus species, but all should be treated as endangered.

Rarely seen in cultivation, S. uncinatus need mineral-rich, very well-drained soil or will rot and die. Good ventilation and full sun are also a must. Keep the plants totally dry in winter months, and they can stand temperatures well below zero. Fertilize in spring, remembering that succulent plants need fertilizer rich in potassium, but poor in nitrogen. Water moderately during growth and let soil dry for a few days before watering again.

S. uncinatus seeds are difficult to germinate because they require cold stratification, prolonged soaking or scarification. The seeds of some species can take as long as three years to germinate.

Absolutely Cactus
The Cactus Family – Anderson
Illustrated Encyclopedia of Cacti – Innes and Glass