Stem. - Hairy, three to six inches high. Leaves. - Undivided, oval or lance-shaped. Flowers. - Papilionaceous, . yellow, but few in a cluster. Pod. - Inflated, many-seeded, blackish.

The yellow flowers of the rattlebox are found in the sandy meadows and along the roadsides during the summer. Both the generic and English names refer to the rattling of the loose seeds within the inflated pod.