Scientific Name: Crotalaria spectabilis

Common Name: showy rattlebox

Other Common Names: showy crotalaria

Leaves: 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.

Identifying Characteristics: A summer annual weed with relatively showy yellow flowers and distinctive seedpods. Leaves that are widest at the apex and taper to the base. Also the bright yellow flowers and distinctive seedpods help to distinguish this weed from most others.

Flower Seed Head: flowers occur on elongated inflorescences (racemes) and are stalked from a central axis, large, showy, and bright yellow in color. Flower stalks have a distinctive bract at their base that is approximately 7 to 12 mm long and 5 to 9 mm wide.

Seed Fruit: A legume that is 1 to 2 inches in length and takes on the appearance of an inflated cylindrical pod. Fruit turn brown to black when mature and the seed within the fruit often become unattached resulting in a rattlebox; sound when shaken.

Where Found: Showy crotalaria is primarily a weed of agronomic crops and may be found from Virginia to Missouri and southward.

  • Life cycle: summer annual

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Fabaceae

  • Leaf arrangement: alternate

  • Leaf shape: oval

  • Ochrea: Not Present

  • Leaf margin: entire

  • Stem hairs: no hairs

  • Flower color: yellow

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: has hairs; no hairs

  • Flower diameter: pencil

  • Flower symmetry: bilateral symetry

  • Root structure: taproot

  • Leaf stalk: shorter than leaf