Perennial herb 20 - 40 cm tall Stem: upright. Flowers: in a loose, branched cluster, long-stalked, white, often tinged dull purple, 1 - 2 cm long. Sepals four, 5 - 8 mm long. Petals four, much longer than sepals. Stamens six. Fruit: a narrow pod, upright, ascending, 2 - 4 cm long, cylindrical. Rhizome: thick, continuous (not jointed or narrowing). Basal leaves: similar to stem leaves but with longer leafstalks. Stem leaves: usually two, opposite or nearly so, short-stalked. Leaflets three, twice as long as wide, coarsely toothed. Terminal leaflets diamond- egg-shaped. Lateral leaflets obliquely egg-shaped.
Similar species: The similar Cardamine concatenate differs by having three whorled leaves and leaf segments that are narrowly oblong to lance-shaped.
Habitat and ecology: Uncommon in the Chicago Region. Has been found growing in mesic woods and calcareous springy ground in Berrien County, Michigan. Was also found along a roadside in Kane County, Illinois.
Occurence in the Chicago region: native
Etymology: Cardamine comes from the Greek word kardamon, which refers to plants in the cress family. Diphylla is Latin for "two-leaved."
Rhizome continuous; stem glabrous, 2-4 dm; cauline lvs commonly 2, opposite or nearly so; lfls 3, coarsely crenate-toothed, half as wide as long, the terminal rhombic-ovate, the lateral obliquely ovate, obtuse to rounded at base on the broad outer side; basal lvs similar to the cauline; hairs of the lf-margins appressed, very short, ca 0.1 mm; sep 5-8 mm; pet 11-17 mm, dull purplish; frs 2-4 cm; 2n=96. Rich woods; Que. and N.B. to Minn., s. to N.C., Ga., and Ala. Apr., May. (Dentaria d.; D. incisa, a form with narrower, laciniately toothed lfls.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.