Opuntia macrorhiza, also known as the prairie pricklypear, western pricklypear, twistpine pricklypear, or plains pricklypear (a name more commonly given to Opuntia polyacantha), is a common, widespread species of cactus native to North America.
Description O. macrorhiza is one of the shorter species of the genus, usually tall (but rarely over ) and in diameter. O. macrorhiza grows horizontally to around . forming wide clumps. Flowers are showy and bright yellow, often with red markings near the base of the petals. Fruits are narrow, red, juicy and edible.Flora of North America, Opuntia macrorhiza Engelmann, 1850. Western pricklypear
Distribution and habitat The species prefers well-drained, sandy or gravelly soils, mostly in grassland areas. It grows at elevations of . It is found throughout the Great Plains of the United States, from Texas to Minnesota, and west into the Rocky Mountain states to New Mexico, Utah, and perhaps Idaho, with sporadic populations in the Mississippi and Ohio Valleys.United States Department of Agriculture Plants Profile It is also reported from northern Mexico in the states of Chihuahua, Sonora, Coahuila, Nuevo León, Durango, Tamaulipas, and San Luís Potosí.,Encyclopedia of LifeBiota of North America Program, 2014 county distribution mapSEINet, Southwestern Biodiversity, Arizona chapter photos, description, distribution map though all Arizona and Mexican records should be considered with caution due to confusion with other similar species. The species is cultivated as an ornamental in other locations.
Subdivisions Some subspecies and varieties have proposed within the species. None are accepted by Plants of the World Online , which treats Opuntia macrorhiza subsp. pottsii (Salm-Dyck) U.Guzmán & Mandujano and Opuntia macrorhiza var. pottsii (Salm-Dyck) L.D.Benson as the separate species Opuntia pottsii.
References
External links Opuntia macrorhiza photo gallery at Opuntia Web field-based description by Art Gibson