Setaria is a widespread genus of plants in the grass family. The name is derived from the Latin word seta, meaning “bristle” or “hair”, which refers to the bristly spikelets.
The genus includes over 100 species distributed in many tropical and temperate regions around the world, members are commonly known as foxtail or bristle grasses. Native to Europe, but it is known throughout the world as a common weed. It grows in lawns, sidewalks, roadsides, cultivated fields, and many other places. This annual grass grows 20 centimeters to well over a meter in height, its mostly hairless stems ranging from green to purple-tinged in color. The leaf blades are hairless on the upper surfaces, twisting, and up to 30 centimeters long. The inflorescence is a stiff, cylindrical bundle of spikelets 2 to 15 centimeters long with short, blunt bristles. The panicle may appear yellow or yellow-tinged.