Purple Prickly Pear Cactus Opuntia Santa-Rita is a bushy succulent shrub to 2 m high and 3 m wide with a distinct, though short trunk. It a very attractive species with reddish or violet-purple pads. Small plants seem to be the most colorful. The yellow flowers are stunning on the purple pads in spring, definitely an eye-catcher.
Stem segments: Round, ovate or obovate sometimes broader than long, not easily detached, 5-20 cm across, thin, nearly smooth, glabrous, glaucous blue-green, when under stress with reddish or violet-purple coloring around the areoles and along the edge; this coloring is more pronounced during winter.
Areoles: 6-8(-9) per diagonal row across mid-stem segment, oval to round, sometimes reniform, c. 3 mm in diameter when young, but increasing with age to about 6 mm, 1.5-2.5 cm apart. The new areoles bear much wool and many short glochids up to 6 mm long. They are yellow to tannish brown in color dense in crescent at adaxial edge of areole, nearly encircling areoles, and in subapical tuft, of even height. The growth of the wool and glochids on old stem pads sometimes produces an elongation of the areole structure outward.
Spines: Not numerous, new stem segments often being spineless or with 1 spine present on only a few edge areoles. Older segments may have 2-3 spines in the upper areoles only. Spines are needle-like, deflexed to erect, straight or slightly curved, flexible, light reddish brown to pink with the upper parts yellowish or mottled with yellow, sometimes almost all black, 2-6.2(-10) cm long.
Flowers: Yellow with bright red bases, 7.5-9(-10) cm in diameter. Inner tepals yellow throughout, fading orangish, 25-45 mm; filaments pale yellow throughout or pale yellow proximally, white distally; anthers pale yellow; style white; stigma lobes light green.