Setaria viridis is a species of grass known by many common names, including green foxtail green bristlegrass, and wild foxtail millet. It is sometimes considered a subspecies of Setaria italica. It is native to Eurasia, but it is known on most continents as an introduced species and is closely related to Setaria faberi, a noxious weed. It is a hardy grass which grows in many types of urban, cultivated, and disturbed habitat, including vacant lots, (Wikipedia)