This alien annual has become a serious invasive problem of woodlands in east-central states. It was first recorded in Ky. during the 1930s (B), and by the 1980s it had become widespread across most of the state. It is especially abundant on damp medium-acid soils that have been exposed along floodplains or trails. It is generally avoided by herbivores, and often associated with cattle or high deer populations. However, cattle can occasionally consume it with relish, perhaps early in the growing season (M. Hutchison, pers. comm.). Leaves have a distinctively paler (shiny to silvery) zone along the midvein.