Showy Rattlebox/Crotalaria, Rattlebox

Crotalaria spectabilis

kroh-tuh-LAR-ee-ah  speck-TAB-ih-liss

Fabaceae

Native to:  Asia

Florida abundance and distribution:  Naturalized and distributed throughout Florida and the Southern United States, Hawaii and Puerto Rico.

Recognition: Annual short shrub 0.6-1.5 m tall with a single ribbed stem green to purple.  Leaves alternate and simple, oblanceolate to elliptical and pubescent, green to yellow-green in color. Petiole approx. 2.8 m long, the stipules are ovate-triangular.  There are about 20-30 very large and showy flowers atop terminal racemes.  Petals yellow with purplish-red veins, the sepals green and smooth.  Fruit oblong, black to brown, approx. 3-5cm long and smooth containing > 20 seeds per pod.  As the fruit matures, the seeds break loose inside the pod and “rattle,” hence the name “Rattlebox.”

Potentially confused species:  There are many different species of Crotalaria found in Florida.  This is the only large species with simple (vs. trifoliate) leaves.

Other:  Good nitrogen fixation. It is toxic to certain animals, especially ingesting the seeds.  Used as a green manure crop.

Contributed by: Andrea Schechter