Cardamine constancei is a rare, narrow-ranged species of perennial rhizomatous forb known by the common name Constance's bittercress.

[5] This species is most often found in moist, low-elevation (400–600 ft (120–180 m)) mixed coniferous forests along rivers, specifically in the redcedar/maidenhair fern habitat type.

[2][6] It is tolerant of light disturbance and appears to favor shaded to partly open habitat, wooded creek bottoms, and hillsides.

[2] Contsance's bittercress only occurs in a known refugium for a number of rare, narrow-ranged endemics such as the Idaho giant salamander and nimapuna tigersnail.

[6] Constance's bittercress is threatened by human habitat modification, specifically mining, road building, logging, and decades of fire suppression.