Smooth Rattlebox

Crotalaria pallida

kroh-tuh-LARE-ee-ah  PAL-lid-duh

Fabaceae (Leguminosae)

Native to:  Africa

Florida abundance and distribution:  Naturalized and distributed throughout Florida but less in the Panhandle, Ga., Al., Ms., N.C., S.C. Hi. and V.I.

Recognition: Alternate, compound, trifoliate leaves, the leaflets oblong to elliptic, the center leaflet larger than lateral leaflets, leaflet margins entire and may end in sharp point.  Stalks ribbed and pubescent; petioles 2-4 cm and very pubescent.  About 10-40 yellow flowers with reddish-brown streaks (veins) sit atop terminal racemes, the bracts linear. Wings oblong, the banner rounded, the keel curved, all pilose.  Pod approx 3.5-3.8 cm long, oblong, with a groove on one side and pubescent, containing between 20-30 seeds.  As fruit matures, the seeds break loose inside the pod and “rattle.”

Potentially confused species:  There are many different species of Crotalaria found in Florida both native and non-native.   This species has characteristically trifoliate leaves with the leaflets more or less elliptic.   Show Rattlebox has simple leaves. 

Other:  Good nitrogen fixation. It is toxic to livestock, especially ingesting the seeds. 

Contributed by: Andrea Schechter