Opuntia cespitosa Opuntia cespitosa Opuntia cespitosa, commonly called the eastern prickly pear, is a species of cactus native to North America. It most common west of the Appalachian Mountains and east of the Mississippi River, where it is found in the Midwest, Upper South and in Ontario. Its natural habitat is in dry, open areas, such as outcrops, glades, and barrens. "Opuntia cespitosa" is a prostrate succulent shrub, usually no more than 1-2 segments tall. It has large white spines, and a low layer of reddish-brown glochids, which break off in the skin if touched. It produces a yellow and red flower
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