Aeschynomene is a principally tropical genus with native American species distributed from 40°N to 35° along the Atlantic coast and from 28°N to 17°S on the Pacific coast. There are about 160 species but cultivars have been released only from americana (Aa; 'Glenn') and falcata (»Bargoo'). Bargoo is a spreading, prostrate, perennial adapted to infertile, well-drained sites. Glenn and Florida common Aa are upright annuals adapted to seasonally-flooded areas. Aa has been evaluated and used commercially to a greater degree than other species. Studies have shown that Aa plant hight at first defoliation is critical, and plant should be clippled or grazed when 30 to 40 cm tall to increase vigor, leafiness, and nutritive value of regrowth. Crude protein and in vitro digestibility of 20 and 70% have been observed for the grazed portion of well-managed Aa swards. Over 3 yr in Florida, steers gained 0.7 kg d- 1 on grass-Aa pastures. Although used commercially in Florida, major limitations of Aa are that it is an annual and drought-induced stand failures are common.