Although historically widely distributed within the Illinois and Mississippi River floodplain, this species is now reduced to fewer than 20 locations. Like many endangered plants, Boltonia decurrens is dependent upon specific environmental conditions. Believe it or not, this plant is successful with periodic disturbance from major floods. Floods open land to full sun and remove silt build-up. Today, the natural flood regime has been altered by dams and levees, and its former habitat is predominately agricultural land. Additional human activities such as regular cultivation and heavy herbicide use are also threats to its continued survival.