Opuntia macrocentra 4 millimeters in length with a broad notch on one side and prominent ridge. Because of its striking stem and bloom color the "Opuntia macrocentra" cactus is cultivated as an ornamental plant for drought tolerant and native plant gardens, and as a potted plant. Like many other cacti in the "Opuntia" genus, the fruit produced by "Opuntia macrocentra" is edible. Collection of this cactus, and its fruit, is restricted in some areas for conservation needs. Opuntia macrocentra Opuntia macrocentra, the long-spined purplish prickly pear or purple pricklypear, is a cactus found in the lower Southwestern United States and Northwestern Mexico.
Opuntia arenaria Opuntia arenaria Opuntia arenaria was considered a variety of "O. polyacantha" by many botanists, and is still treated that way in the Flora of North America. However, "O. arenaria" is diploid and "O. polyacantha" is tetraploid. It was described by Engelmann in 1856. "Opuntia arenaria" can grow in soil that is essentially pure sand. It has rhizomes up to 1.5 m long that give rise to above ground shoots with small cladodes that are 4-7 x 2–3 cm in size. Major spines are found in the distal areoles and are often reflexed, up to 30 mm long. Minor spines are