ABSTRACT
Many species of cactus occur on the Great Plains. This chapter focuses on plains pricklypear, Opuntia polyacantha Haw., the most abundant and widespread species. Plains pricklypear is a common associate of blue grama, Bouteloua gracilis Lag., and buffalo grass, Buchloe dactyloides Engelm., on the shortgrass steppe. It occurs on clay loam to sandy loam soils but is rarely found on pure sand. The root system of plains pricklypear consists of larger lateral roots somewhat woody in nature, extending 1.2 m or more. The method of reproduction which is most pertinent to attempts to mechanically control pricklypear is its ability to produce roots from detached pads or joints. "Conventional Wisdom" has long indicated that pricklypear cactus increases on overgrazed ranges. One of the first statements to this effect was by Weaver. The studies documenting abundance of pricklypear under different grazing intensities have indicated that grazing has little effect on pricklypear.
