Santa Rita Pricklypear
Opuntia santa-rita
Family: Cactaceae
The most distinctive trait most people notice is that this species gets purple with cold weather (or extreme drought stress). The pads will be more blueish green in the summer. Plants get about 5-6’ tall or sometimes a little taller, and they grow a bit wider than tall. Sometimes pads will re-root on the edges making the plant grow even wider. Solid yellow flowers occur in late spring or early summer and they fade to beige or orange. This also helps distinguish this plant from Opuntia macrocentra which is a smaller plant, and usually has red in the throat of its yellow flower. Fleshy purple fruits follow the flowers.
Photo by user “turn off your computer and go outside” on iNaturalist
Opuntia santa-rita on SEINET
Plant in full sun. Low water is required but watering once or twice a month in summer keeps plants healthy, especially when rains are scarce. In containers, water 1-2 times a week in summer, and maybe once a month in winter if there is no rain. Hardy to about 10-15°F.
We recommend watering plants in the summer when there is drought to prevent rots. During droughts plants will have natural root dye-back, and this is normal. But during extended droughts like the two year drought of 2019-2020, plants had excessive root dye-back and when the rains finally came, many plants just rotted. Many people thought that the really wet summer is what rotted the cacti, but it was the response to copious moisture coming into contact with lots of dead roots, and those rots chased up into the plants.
Flowers are very important for native bee species, though numerous other pollinators use the flowers. The seeds of the dried fruits are eaten by birds and many other animals. Prickly pear plants provide important habitat for birds, native rodents like packrats, and numerous other animals. Larval host for the tineid moth Dyotopasta yumaella, the grass moth Dicymolomia opuntialis, the snout moth Laetilia dilatifasciella, and the grass moth Pseudoschinia elautalis.
Opuntia is from Latin root puncti for prickled. The specific epithet, santa rita, is named for the Santa Rita Mountains in Arizona where they are found. There are approximately 176 species currently accepted for the genus. Like most true cactus species, prickly pears are native only to the Americas. Through human action, they have since been introduced to many other areas of the world.
Native to the Chihuahuan Desert of northern Mexico and the Big Bend area of southwestern Texas.
One way to distinguish this from the other purple pricklypear cacti is that this species regularly gets much larger. Photo by CK Kelly, iNaturalist
The flowers on this species are solid yellow, though the older flowers may fade to orange or beige. Photo by CK Kelly, iNaturalist
These flowers have "faded" to orange. Photo by Sue Carnahan, iNaturalist
The plants have a more blueish green hue in the warmer seasons. The plants tend to lack longer spines, though this individual has some longer spines. The fact the plant is much more robust and growing larger probably points to it being Opuntia santa-rita rather than O. macrocentra which is the species that usually has the longer spines. When identifying cacti, sometimes you need to go off of a few traits, since cacti sometimes have unpredictable morphology. Photo by CK Kelly, iNaturalist.