Opuntia diploursina Opuntia diploursina Opuntia diploursina is a species in the Cactaceae family, that grows near and in Lake Mead National Recreation Area and northward across Nevada's Mormon Mesa, into Utah. This species is a close relative and probable ancestor of "Opuntia erinacea", but "...differs in minor spines more closely appressed to pad surface, spines smaller in diameter and more flexible, inter-areolar distance less, upright growth habit, larger fruit with longer, more flexible spines, larger seeds, and diploid chromosome number (2n=22)". "Opuntia diploursina" is also related to another diploid species, "O. trichophora", but differs from that species, as stated in the original
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