Opuntia (2004)

By Eric Driskill (February 2004)

Opuntia is the most widespread and common genus of cacti. Many plants have been moved in and out of the genus. It currently has at least 181 species and 10 naturally occurring hybrids. Opuntias range from Canada to southern Argentina.

Often the genus is separated into at least two groups. The platyopuntias have round, flattened joints called pads. They are commonly called Prickly Pears, as they have spiny, often edible fruit. Cylindropuntias have long, cylindrical joints and are commonly called “chollas.”

A distinctive feature of opuntias that is shared by only a few other genera is their glochids, which are small, specialized barbed spines borne at the bases of large spines. These can be very irritating if not handled with care.

Opuntias come in all shapes and sizes. Some opuntias are winter-hardy. Some are planted around houses under windows as barriers any thief would hate to encounter.

Several opuntias with white glochids, such as O. microdasys, variety alba, are small and don’t take up much room. One of my favorites is O. basilaris, which is thick-padded and has a purplish hue. Other purple opuntias include O. gosseliniana and O. santarita.

One tip for opuntia owners: If you get glochids on your skin, use duct tape to remove them. It can sometimes retrieve glochids that are hard to find with the naked eye. Better yet, handle opuntias with tongs and keep your hands off them.

I once heard that if you cut a shape in an opuntia pad, each pad that grows off it will form the same shape. I have never tried this because I think it is only a clever story. If you start looking into all the diversity in the genus, though, you just might find one you want to add to your collection.