Opuntia cespitosa in late spring. This species was historically included in a broadly-defined "Opuntia humifusa" group, which is found further to the east. "Opuntia cespitosa" differs from "Opuntia humifusa" in its flowers having a red center. 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,
Opuntia fragilis in). Both the common and scientific names refer to the easily detached stem segments. This is known to be a means of plant dispersal. "Opuntia fragilis" is a small, prostrate plant, rarely more than 4 inches high: joints tumid, fragile, easily detached, oval, elliptical, or subglobose, 1-2 in. long and nearly as thick as broad, bright green: areoles ¼-½ in. apart, with whitish wool and a few white to yellow bristles, which are much longer and more abundant on older joints; spines 1-4, occasionally a few small additional ones, weak, dark brown, the upper one usually longer and stronger than