GIANT FOXTAIL, Setaria faberi
Herrm. 1, lower part of plant; 2, stem with panicle; 3,
spikelets with bristles attached. Annual, reproducing by seed. Stems
3 to 7 feet (0.9 to 2 m) tall, so weak that plants may lodge unless supported
by each other or by other vegetation. Leaves covered with short
hairs on upper surface. Panicle dense, 3 to 8 inches (7.5 to 20
cm) long, bending near base so that head is drooping. Three to six bristles
extend from base of each spikelet. Seed mostly greenish, about 1/16
inch (1.5 mm) long, intermediate in size between seeds of green and yellow
foxtail. Found in cultivated crops, where it is extremely troublesome.