Arrowhead Rattlebox

Annual, Herbs, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Stem hairs hispid to villous, Stems winged or with decurrent stipules, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules green, triangulate to lanceolate or foliaceous, Stipules persistent, Stipules free, Stipules cordate, lobed, or sagittate, Leaves simple, or appearing so, Leaf or leaflet margins entire, Leaflets 1, Leaves hairy on one or both surfaces, Flowers in axillary clusters or few-floweredracemes, 2-6 flowers, Inflorescences racemes, Inflorescence axillary, Inflorescence leaf-opposed, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separ ate, Corolla papilionaceous, Petals orange or yellow, Banner petal suborbicular, broadly rounded, Wing petals narrow, oblanceolate to oblong, Keel abruptly curved, or spirally coiled, Stamens 9-10, Stamens or anthers dimorphic, alternating large and small, Stamens monadelphous, united below, Filaments glabrous, Style terete, Style sharply bent, Style hairy, Fruit a legume, Fruit stipitate, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit inflated or turgid, Fruit glabrous or glabrate, Fruit 11-many seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Crotalaria sagittalis, known as arrowhead rattlebox or just rattlebox, is an annual wildflower native to the United States, Midwestern and Eastern states.