Cardamine raphanifolia. (Broad-leaved cuckoo flower) is a spreading, rhizomatous, deciduous perennial with pinnate leaves divided into paired, ovate to rounded, toothed, dark green leaflets and panicles of white, lilac, or reddish-purple flowers in summer. Cardamine raphanifolia (Broad leaved cuckoo flower) is an edible American water cress with more flower power, needs cool conditions in running water to do best.