Boltonia decurrens is a rare species of flowering plant in the aster family known by the common names decurrent false aster and claspingleaf doll's daisy. It is native to the floodplains along the Illinois and Mississippi Rivers in the United States, where the habitat has been drastically altered, leading to its decline. The plant was once distributed across 400 kilometers of riverside forest from LaSalle, Illinois, to St. Louis, Missouri. As the rivers and riparian habitat alongside them have been developed, the plant's distribution has been fragmented into about 20 separate populations, mostly in Illinois. At one point it was thought to have been extirpated from Missouri, but a few populations have been located near St. Louis since the mid-1980s. Despite having declined over time, severa