Foxtail refers to several species of grasses belonging to the genus Setaria. These plants are characterized by their bushy flower spikes that resemble a fox's tail, hence the name. Foxtail grasses are commonly found in temperate and tropical regions and can grow in various habitats, including fields and roadsides. Some species of foxtail, such as Setaria viridis and Setaria faberi, are considered weeds due to their rapid growth and ability to outcompete native plants. They can also pose risks to livestock, as their seeds can become lodged in animals' mouths or digestive tracts, leading to health issues.