Technical Abstract: Both native and non-native forage grasses other than switchgrass are less commonly considered as potential lignocellulosic biomass feedstocks for bioenergy in the United States. The forage grasses consist of temperate cool-season (most commonly C3) grasses as well as the tropical or sub-tropical and warm-season (C4) grasses. They have potential as feedstocks from the fact that they have generally been researched and used as a pasture or hay crop and are currently grown over millions of acres of fertile as well as Conservation Reserve Program (CRP) land throughout the United States. In general, research has only recently begun concerning the potential as a renewable energy resource on the majority of these species. This chapter does not attempt to address all of the 10,000 species of grasses, of which 47% are C4, but is limited to those considered to have the greatest potential of contributing to the billions of tons of biomass needed for replacement of fossil fuels over the coming years.