Perennial herb with rhizomes to 2 m tall Flowers: in dense, branched clusters (raceme), which are borne near the ends of branches. Racemes small. Petals four, white. Stamens six. Fruit: a small pod (silicle), 2 mm long, nearly orbicular, rounded at both ends (not notched), sparsely hairy, wingless. Lower leaves: long-stalked, to 30 cm long, to 8 cm wide, hairless or nearly so. Upper leaves: alternate, mostly 1 - 4 cm wide, lance-shaped to narrowly egg-shaped, sometimes toothed, hairless or nearly so.
Similar species: Lepidium densiflorum, L. ruderale, and L. virginicum are all similar, but have linear to lance-shaped stem leaves which do not reach 1 cm wide.
Flowering: June to early August
Habitat and ecology: Introduced from Eurasia. Found along roads (mostly highways) and railroads. Along the coast of New England, this plant was observed growing in saline soil.
Occurence in the Chicago region: non-native
Etymology: Lepidium comes from the Greek word lepis, meaning scale, which refers to the shape of the silicles. Latifolium means "wide leaves."
Rhizomatous perennial to 2 m; herbage glabrous or nearly so; lower lvs long-petioled, to 30 נ8 cm; cauline lvs lanceolate to narrowly ovate, entire to dentate, the main ones 1-4 cm wide; infl paniculately branched, with many short racemes that do not elongate; stamens 6; fr sparsely hirsutulous, suborbicular, 2 mm, wingless, rounded at both ends, not notched; stigma subsessile; 2n=24. Native of s. Europe and w. Asia, established along the coast from Mass. to L.I. and at widely scattered stations elsewhere.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.