What is "crotalaria sagittalis"

Rattlebox \Rat"tle*box`\ (r[a^]t"t'l*b[o^]ks`), n.

1. A toy that makes a rattling sound; a rattle.

2. (Bot.)

   1. An American herb ( Crotalaria sagittalis), the seeds of which, when ripe, rattle in the inflated pod.

   2. Any species of Crotalaria, a genus of yellow-flowered herbs, with inflated, many-seeded pods.