Opuntia macrorhiza

Opuntia macrorhiza Engelm. is a common and widespread species of cactus with the common names "Plains Prickly Pear" or "Twist-spine Prickly Pear." It is found throughout the Great Plains of the United States, from Texas to Minnesota, as well as in the desert and Rocky Mountain states from Arizona to Idaho, with sporadic populations in the Mississippi and Ohio Valleys.^[1] It is also reported from northern Mexico, in the states of Chihuahua, Sonora, Coahuila, Nuevo León and San Luís Potosí.^[2] The species is cultivated as an ornamental in other locations.

The species prefers dry, sandy or gravelly soils. It is one of the shorter species of the genus, rarely over 30 cm (1 foot) tall, spreading horizontally and forming large clumps. Flowers are showy and bright yellow. Fruits are red, juicy and edible.

Several varieties have proposed within the species. More study is needed to determine whether these should continue to be recognized as varieties, elevated to species status, or regarded as mere synomyms. Numerous names have been published, also now regarded as synonyms of O. macrorhiza.

Opuntia macrorhiza Engelm., Bost. J. Nat. Hist. 6: 206, 1850.^[3]

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