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 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