Annual or biennial herb with a taproot mostly 40 cm - 1 m tall Stem: stout, upright, branched, mostly over 3 mm thick, sometimes sparsely hairy below. Leaves: alternate, pinnately divided (the lower leaves), lance-shaped to oblong- reverse egg-shaped, upper leaves slightly toothed, thick. The middle stem leaves are generally winged toward the lobed base, looking more or less stalkless. Flowers: in branched clusters (racemes). Sepals four, ascending. Petals four, yellow, 1.5 - 2.5 mm long, about as long as sepals, bases narrowed. Stamens six. Fruit: a pod (silique), 2.5 - 5 mm long, more or less round in cross-section, constricted at the middle.
Similar species: No information at this time.
Flowering: late May to early September
Habitat and ecology: Common in and along streams and ditches. Also found around ponds and in other moist areas.
Occurence in the Chicago region: native
Etymology: Rorippa possibly comes from the Latin roro, meaning "to be moist," and ripa, meaning riverbank. Palustris means "marsh-loving."