My son Orion standing next to a large barrel cactus
May 2009 Growing up to nine feet tall and nearly twenty inches in diameter, a large barrel cactus may sometimes be mistaken for a young saguaro from a distance. A look at the spines is an easy way to distinguish between the two: barrels have thick, yellowish or red hooked spines; saguaro spines are slender, straight and silvery gray. Both have pleated stems that expand and contract to allow maximum water storage when rains are plentiful. But a barrel will never grow arms, as does a saguaro after fifty years or so.
The Deem Hills are home to thousands of barrel cacti, known to botanists by their Latin name, Ferocactus cylindraceus. The prefix “Fero-” is derived from the Latin word ferox, which means wild or fierce. This is a good description for these robust cacti that are well protected by sharp stout spines and are tolerant of extreme heat and drought. This species is one of more than twenty kinds of barrel cactus found in North America, five of which are native to Arizona.
Their common name refers to the size, shape and capacity to store water. Historically, many Native American tribes have used the mashed pulp of these hefty cacti for food and moisture, but for most people, attempting to extract water from a barrel cactus requires more energy than it would be worth. The bitter, slimy yellow pulp of the cactus is also mildly toxic, inducing headaches, vomiting and diarrhea. Other creatures are immune to these effects, however, so bighorn sheep, wild burros, jackrabbits and packrats gain some nutrition from barrel cactus if they can manage to gnaw past the spines.
Another type of food produced by barrel cacti is nutritious nectar that seeps from the base of the spines. Ants are especially attracted to the nectar, gathering the sweet liquid to bring to their colonies where it is fed to the growing larvae. In exchange for the nectar reward, ants help defend the cacti from other insects that might devour their flesh. Nearby anthills also create nutrient and moisture rich soils that nourish the cacti.
A crown of yellow or orange flowers bloom from March through June, attracting many types of beetles and bees that rummage around as they collect pollen. These insects provide the important service of pollinating the flowers so that they can produce fruit and seeds that may grow into the next generation of cacti. The fruits look like tiny pineapples, but are filled with seeds and very little pulp. Humans, as well as many species of wildlife relish the buds, flowers, seeds and fruits, much like those of other types of cacti, such as cholla and saguaro, whose buds and fruits were a mainstay of traditional Native American diets. Each barrel is anchored to the rocky slopes that it lives on by shallow roots that soak up any moisture that falls throughout the year, whether it be a light winter sprinkle, or a late summer deluge. When the earth is soaked, the cactus will produce a network of new roots to increase the uptake of water, ensuring its survival through long periods of drought. The shallow roots are a weakness for these otherwise hearty cacti, since they are easily toppled by erosion or anything else that might disturb the soil around them. Another threat to barrel cacti is vandals and collectors that may damage or poach them from wildlands. Like all other native cacti in Arizona, these plants are protected by State Law. Under Arizona Revised Statutes, it is prohibited to “destroy, dig up, mutilate, collect, cut, harvest, or take” any barrel cactus on state or other public lands without obtaining a special permit. Fines up to $5,000 may be issued for violation of these laws. Barrels are popular landscaping plants, and can be legally purchased at nurseries that have obtained them through sellers with salvage permits, or grown from seed.
Since May 2005, I have written a natural history column for a neighborhood newsletter published by Jennifer Moore called "Our Big Backyard: Natural History of the Deem Hills," and since 2010, "A Suburban Naturalist."All of these columns are reproduced here. Deem Hills is a City of Phoenix Desert Preserve located just north of Happy Valley Road in north central Phoenix, and just west of I-17. The Preserve and adjacent hills comprise over 900 acres of open space with several miles of hiking trails. For more perspectives from the Deem Hills and suburban Phoenix, also check out my companion blog, Kat Tracks.
As a naturalist with a special interest in botany and plant ecology, some of my greatest passions are to explore, photograph and write about native plants. If I can spark an awareness or interest in natural history in others along the way, that is my greatest reward.