Herbs, sometimes slightly woody, with simple (or in some tropical species 3-7-foliolate) leaves, and racemose flowers. Calyx 5-toothed, slightly 2-lipped. Standard orbicular or ovate, often cordate; wings oblong or obovate; keel curved. Stamens monadelphous, their sheath deeply cleft; anthers of 2 forms, alternating with each other, the one small, versatile, the other larger. Ovary sessile or short-stalked; style more or less curved. Pod oblong or globose, inflated, coriaceous or membranous, many-seeded, the seeds loose at maturity. [Greek, a rattle.]

About 250 species, mainly natives of tropical regions. Besides the following, some 7 others occur in the southern and southwestern United States. Type species: Crotalaria lotifolia L.

1. Crotalaria Sagittalis L. Rattle-Box

Fig. 2459

Crotalaria sagittalis L. Sp. Pl. 714. 1753.

Annual, erect or decumbent, villous-pubes-cent, branching, rarely over 1° high. Leaves simple, oval, lanceolate or oblong, acute or obtusish at the apex, rounded at the base, entire, nearly sessile, 1'-2 1/2' long, 2"-8" wide; stipules persistent and united, decurrent on the stem, sagittate above, or the lower wanting; peduncles 1'-4' long, 2-4-flowered; pedicels 1"-3" long; flowers yellow, 4"-6" long, the corolla about equalling the calyx; pod oblong, glabrous, nearly sessile in the calyx, 1' long, 4"-5" in thickness, much inflated, nearly black at maturity; seeds shining.

In dry open places, Vermont to Florida, Minnesota, South Dakota, Arkansas and Mexico. Also in Jamaica. June-Sept. Wild pea. Loco-weed.

2. Crotalaria Rotundifòlia (Walt.) Poir. Prostrate Rattle-Box

Fig. 2460

Anonymos rotundifoha Walt. Fl. Car. 181. 1788. Crotalaria sagittalis var. ovalis Michx. Fl. Bor.

Am. 2: 55. 1803. Crotalaria rotundifolia Poir. in Lam. Encycl.

Suppl. 2: 402. 1811. Crotalaria ovalis Pursh, Fl. Am. Sept. 469. 1814.

Perennial by a deep somewhat woody root, the slender branches usually prostrate. Pubescence mostly dense, brownish, spreading or ascending; leaves broadly oblong or oval, obtuse at both ends, or narrowed at the base, paler beneath than above, \'-\\' long; petioles 1"-2" long; upper stipules usually distinctly sagittate, the lower much smaller, or often wanting; peduncles lateral, 2'-6' long, slender, 2-6-flowered; flowers usually distant, yellow, 6"-8" long; corolla little longer than the calyx; pod nearly as in the preceding species.

Mostly in dry soil, southern Virginia to Florida, Missouri and Louisiana. May-Aug.

Crotalaria Púrshii DC, of the southern United States, another perennial deep-rooted species, but with leaves linear to oblong, stems erect or ascending, and. merely puberulent, is recorded as entering our area in southern Virginia.