GREEN FOXTAIL, Setaria Yiridis (L.) Beauv. 1, entire plant; 2, seeds. Annual, similar to giant foxtail but smaller, usually growing 1 to 3 feet (0.3 to 0.9 m) tall. Stems erect. Leaves hairless. Panicle dense, 1 to 3 inches (2.5 to 7.5 cm) long, erect, except near tip, which bends slightly. One to three bristles below each spikelet. Seed green, about 1/16 inch (1.5 mm) long, but uniformly smaller than that of giant foxtail. Found generally throughout region. One of the most widespread grass weeds. Several types of S. viridis in the region vary greatly from the above description. They may grow to 6 or 7 feet (1.8 to 2 m) tall and may have panicles as large as or larger than those of giant foxtail. Some types may have purple bristles. The seed, however, is always smaller than that of giant foxtail. Some authors have separated these types of S. viridis into varieties and refer to them by such names as giant green, robust white, and robust purple foxtails.