Botanical description: The tail-like seed head of Setaria viridis can be seen nearly everywhere at the height of summer - it is one of the most ubiquitous members of the urban flora for its ability to flourish in highly disturbed areas. Introduced to North America as a forage grass in the early 1800s, green foxtail grows spontaneously along railroad tracks and highway medians, in vacant lots and neglected parks. Green foxtail rarely enters established natural areas, requiring the bare earth of disturbed environments to germinate. If conditions are amenable, Setaria can produce multiple generations of plants in one season. The plants develop very quickly, cycling through flowering and seed production early in the season, with the ability to spread through suitable habitat with ease. Small tufts of erect blades emerge in the spring. Soon thereafter, these annual plants shoot up slender flower stalks that terminate in a bottlebrush-like collection of bristled florets which nod under the weight of seeds. Many insects feed on the species including grasshoppers, leaf beetles, aphids, and stinkbugs. Several species of upland and wetland birds eat the seeds and foliage, as do small mammals such as mice, squirrels and domestic cattle - all of which are dispersal vectors.