green foxtail
Quick Summary
Green foxtail (Setaria viridis) is a European grass that has become a common and troublesome weed in North America. It belongs to the genus Setaria, also known as bristlegrass, which includes nearly 125 species of annual and perennial grasses found in warm regions worldwide.12
Foxtails are characterized by their seed clusters, which resemble a fox's bushy tail and can have barbs that attach to animals. While most foxtail species are considered weeds, some, like foxtail millet (S. italica), have economic value as forage grasses. Green foxtail and yellow foxtail (S. pumila) are frequently found in disturbed areas and cornfields.2
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

