Opuntia the Americas. Through human actions, they have since been introduced to many other areas of the world. Prickly pear species are found in abundance in Mexico, especially in the central and western regions, and in the Caribbean islands (West Indies). In the United States, prickly pears are native to many areas of the arid, semi-arid, and drought-prone Western and South Central United States, including the lower elevations of the Rocky Mountains and southern Great Plains, where species such as "Opuntia phaeacantha" and "Opuntia polyacantha" become dominant, and to the desert Southwest, where several types are endemic. Prickly pear cactus is
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