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 readily between species. This can make classification difficult, yielding a reticulate phylogeny where different species come together in hybridization. Also, not all species listed here may actually belong in this genus, meaning that "Opuntia" is not a monophyletic group. "Opuntia" also has a tendency for polyploidy. The ancestral diploid state was 2n=22, but many species are hexaploid (6n = 66) or octaploid (8n = 88). Chollas, now recognized to belong to the distinct genus "Cylindropuntia", are distinguished by having cylindrical, rather than flattened, stem segments with large barbed spines. The stem joints of several species, notably the jumping cholla ("Cylindropuntia