Showy crotalaria is primarily a weed of agronomic crops and may be found from Virginia to Missouri and southward. Erect, reaching 6 feet in height, stout, and green or purplish in color. Stems become waxy and somewhat angled with age. Cotyledons are bean-shaped, thick, dark green above and light green below. First true leaves are alternate and widest at the apex and tapering to the base.
Leaves are without hairs on the upper surface and covered with appressed hairs on the lower surface.
Alternate, approximately 2 to 6 inches long, widest at the apex and tapering to the base. Leaves are without hairs on the upper surface and covered with appressed hairs on the lower surface. Leaves occur on short petioles. Stipules also occur at the base of the petioles but usually persist only for a short time. Flower stalks have a distinctive bract at their base that is approximately 7 to 12 mm long and 5 to 9 mm wide.