||The native warm-season (C4) grasses that have the most potential for use in agriculture are switchgrass [Panicum virgatum], big bluestem [Andropogon gerardii ], and indiangrass [Sorghastrum nutans]. They are tall warm- season (C4) grasses that were the dominant grasses of the North American Tallgrass Prairie. The initial breeding work on these grasses began in the emid 1930’s as a result of efforts to reseed land damaged by erosion, i.e., the "dust bowl", in the Great Plains of the United States. As a result of long-term breeding programs maintained by USDA’s Agricultural Research Service and Natural Resource Conservation Service and a few state universities, a basic set of cultivars of these grasses have been developed for most geographic regions. In comparison to most cultivated species, however, the breeding work on these species has been limited and substantial genetic improvements are still feasible. Substantial genetic variation exists among and within populations of switchgrass, big bluestem and indiangrass for most agronomic traits, particularly forage yield and quality. Improved breeding methods and equipment are available to develop improved cultivars of these species for use in grassland agriculture.