Prickly pear cactus, our state plantBy Delmar Cain on August 30th, 2011
The prickly pear cactus was selected by the Texas Legislature in 1995 to be the State Plant of Texas. That information probably comes as a bit of a surprise to some of you as it did to me. But on reflection I can think of no more appropriate choice to be representative of the Lone Star State.
The “prickly pear cactus” is not the name for a single species. According to the U. S. Department of Agriculture “prickly pear” in the cactus family is the common name for the genus Opuntia, which contains fifty-nine different species. Included in the genus are species that I would not have called a prickly pear. For instance the tasajillo (Opuntia leptocaulis) or Christmas cactus as it is sometimes known and the tree cholla (Opuntia imbricata) or walkingstick cholla are in the prickly pear genus, as you can see by the scientific names.
When I think of a prickly pear cactus, I think of a cactus with shallow roots, flattened oblong 4 to 10 inch pads, joined either end to end or branching, that reclines or grows to a total height of about 4-6 feet with green or red pear-shaped fruit pods in the late spring. Technically I have found that what I have described is one of several species in the genus Opuntia, subgenus Opuntia. The one we see most often in the Boerne area is the Lindheimer prickly pear (Opuntia engelmannii var. lindheimeri).
Oh, there is something that I failed to mention. The prickly pear that I know silently, but effectively proclaims, “Don’t mess with me, Texan!” Those flattened joints or pads called cladodes, cladophylls or phylloclads have both long spines and smaller ones called “glochids” that can put some hurt on the unwary or the unbeliever. The smaller of the two are too big to leave in your skin, but almost too small to see to get out. Misery.
So why is the prickly pear cactus such a well-chosen state plant for Texas? First, it is Texas tough. To survive and thrive in Texas, which includes habitats as diverse as the Piney Woods of East Texas and the Trans-Pecos region of West Texas that includes a part of the eastern range of the Chihuahuan Desert is impressive. Areas in the Piney Woods may averages 50 plus inches of annual rainfall, while areas of the Trans-Pecos may average as little as 8 inches. A single species of prickly pear does not cover that entire range but similar varieties can be found in the whole of the area.
Second, the prickly pear is useful to wildlife and domestic animals. Small mammals and birds feed on its fruit and find that the spaces between its spiny pads provide excellent protection. Because each fruit or tuna produces a large number of sweet, tasty and nutritious seeds (more than 200 per fruit) larger mammals from raccoons to horses have a reliable food source in the August heat when many other plants are struggling. And we have all heard that when the thorns are removed by burning in times of drought, cattle and other domestic animals will eat and survive on the pads.
Third, the prickly pear has a well-documented history of being useful to man. Matt Turner, who spoke at one of our Native Plant Society meetings here in Boerne, reports in his book, Remarkable Plants of Texas that, “Practically every part… including stems, flowers, fruit, seeds, thorns, and even sap has been used from prehistoric to contemporary times by every culture from Native Americans and Spanish colonial to Hispanic and Anglo Texians, cowboys and even connoisseurs of southwestern cuisine.”
Each group exhibited its creativity in turning the abundant resource into foods, into medicines and surprisingly into utensils. Even the pests of the prickly pear have been used with the cochineal bugs, which feed on the pads, providing the red dye for the military coats of the British.
Darrell Ueckert, with the Texas Agricultural Experiment Station in San Angelo, reported in a 2011 abstract on “Pricklypear ecology” that some variety of the prickly pear cactus occurs on some 30.7 million acres of rangeland in the western two-thirds of Texas. In some areas the prickly pear’s abundance is controlled. But in 80 percent of the counties it is considered to have positive values for wildlife and in 60 percent of the counties it is considered to have positive values for livestock production.
Those are enough good reasons for me to applaud the, dare I say it, wisdom of the Legislature in declaring the prickly pear our State Plant. Well, there I have said it.
Although the prickly pear is one tough plant it is not invincible, contrary to the opinion of some who have tried to eradicate it from their land. It has its own set of native enemies that it has successfully competed against for millennia.
The Cactaceae family of plants, which includes the prickly pear, is found only in the New World, meaning that the plants in this family are indigenous only to the North and South American continents. However, many of the species, either because of their uniqueness or utility or both, have been introduced into other parts of the world. Because of its ability to survive in harsh climates and to reproduce both from seeds and by sprouting from fallen pads, the prickly pear, after being introduced in some locales, has subsequently reproduced its way into the nuisance class of plants needing control.
By 1925 the Aussies decided to fight some of their rapidly spreading cacti through biological control. They introduced in that year a cactus moth from Argentina, with the B-movie science fiction scientific name, Cactoblastis cactorum, to control the prickly pear. After it became established Cactoblastis cactorum quickly and almost totally eliminated the prickly pear in Australia.
In our area the prickly pear has its own set of insect pests, including the cochineal and the blue cactus borers (Melitara dentate and Melitara prodeniales), which periodically have an impact on local populations. But the natural enemies of the local pests keep matters in check and our prickly pear populations have until now remain stable. Because Cactoblastis cactorum escaped from its natural enemies, which did not make it through Argentine customs, the invited visitor from South America moved unchecked through the introduced prickly pear in Australia.
The cactus moth story might be considered an example of an excellent recovery from a near disaster if the moths had just faded away in Australia. But because Cactoblastis cactorum was such a success in Australia, folks in the Caribbean transported it there in the 1950’s also to control a rampant prickly pear population. Unfortunately the moths didn’t read the script and stay in the Caribbean.
In 1989 Cactoblastis cactorum landed in Florida and has now moved as far west as Jefferson Parish in Louisiana.
In an April 27, 2011 news release, the Texas Parks and Wildlife Department indicated that the likelihood is high that it will make it to the Texas coast. The concern is that without its natural predators the moth will spread unchecked into Texas, the Southwest and into Mexico, where the economic value of the prickly pear is in the millions of dollars.