Cardamine pratensis var. palustris Wimm. & Grab.  
Family: Brassicaceae
cuckoo-flower
Cardamine pratensis var. palustris image
Etymology: Cardamine: originally from the Greek kardamon used by Dioscorides for some cress, maybe used in treating heart ailments
Plants: erect, perennial, 8"-20" tall forb
Leaves: 3-8 basal leaves, long-stalked, rounded to kidney-shaped, pinnately-divided with the end leaflet largest; lower stem leaves similar to the basal leaves, then the leaflets all become linear
Flowers: white, 4-parted, 1/2"-1" wide; inflorescence a dense cluster (raceme) of stalked flowers; blooms April-July
Fruits: long, thin, mostly erect pods
Habitat: wet; cold; bogs, limy swamps
Conservation Status: Native
Cardamine pratensis var. palustris image
Merel R. Black  
Cardamine pratensis var. palustris image
Kenneth J. Sytsma  
Cardamine pratensis var. palustris image
Emmet J. Judziewicz  
Cardamine pratensis var. palustris image
Botanical Illustration