Ornamental grasses have become popular mainstream ornamental landscape plants due to their natural appearance and low maintenance requirements that make them perfect for today's sustainable landscapes. Ornamental grass sales in the united States were $124,261,000 in 2009, up from $61 million in 2003, the first year the National Agricultural Statistic Service collected data (USDA 2009). Ornamental grass research has focused primarily on commercial production, cold hardiness, propagation, and invasiveness. Three popular nonnative genera, Cortaderia, Miscanthus, and Pennisetum, have become invasive plants in warmer areas of the United States, although this varies widely by region. The native switchgrass (Panicum virgatum) and giant miscanthus (Miscanthus _ giganteus) show potential for biomass fuel resources. Information is presented on 16 native and 22 nonnative major ornamental species that currently make up the majority of ornamental grasses in use in the United States today.