Annual, stem pubescent, winged. Leaf paripinnately compound, leaflets 2, 2-6 cm long, 7-30 mm broad, elliptical or ovate-oblong. Stipules 1.5-2.5 cm long, semisagittate. Inflorescence 1-3-flowered. Calyx 10-11 mm long, teeth almost equalling the tube. Corolla white, pink, purple, violet or blue in various cultivated forms, 2-3.5 cm long. Fruit 5-7 cm long, 10-12 mm broad, pubescent, 8-seeded.