MOTHERWORT, Leonurus cardiaca L. 1, upper portion of plant; 2, base of plant; 3, seed. Perennial, reproducing by seed and rhizomes. Roots extensive but shallow. Stems 2 to 5 feet (0.6 to 1.5 m) tall, 4-sided, erect, coarse, stiff, nearly smooth, branched near top. Leaves opposite; lower leaves toothed and 3-lobed; upper leaves narrow, notched. Flowers in tight clusters in axils of leaves, spiny and burlike when dry, petals formed into 2-lipped purple or white tube. Seeds borne 4 in a pod, oval, 3 sided, dark red to brown. Found mostly in waste places and noncultivated fields. Usually not troublesome except in low, rich soils.