Corydalis flavula (yellow fumewort) can be found throughout most of the eastern half of the US and also parts of Canada. It is a pioneer species that requires disturbance to thrive. Disturbance (mostly in the form of flooding as it is a floodplain species) helps to keep the overarching canopy at the right density for its light requirements. Because of this requirement it is threatened primarily due to human land use which often results in conversion of habitat to mowed lawns and managed streams and rivers, removing the disturbance and canopy the plant requires.
