ABSTRACT
Various terms have been used to describe grasslands. In North America, "prairie" has been applied to several grass-dominated communities, especially those of the Great Plains, but also including areas containing substantial amounts of shrubs. The Great Plains grassland region of North America is best referred to as a steppe region, and contains several physiographic regions or provinces. The eastern portion, commonly called the tallgrass or true prairie, is characterized by taller grasses, principally Agropyron, Andropogon, and Stipa in the Dakotas. The central steppe region is occupied by a mixture of tall-and shortgrasses; consequently it is usually referred to as the mixed- or midgrass region. The western portion of the steppe region traditionally has been referred to as the shortgrass region, or sometimes the Bouteloua gracilis province. Other grasslands occur, to a limited degree, within the area usually considered the Great Plains. In northwestern shrub steppe areas, bunchgrasses occur, sometimes in conjunction with Bromus spp. and Artemesia tridentata.
