(*διά*, twice, and *στέφανος*, a brother), clasps the 17th in the sexual system, comprehending those plants which bear hermaphrodite flowers with two sets of united stamens, but this circumstance must not be absolutely depended on. They are the *papilionaceae* of Tournefort, the *irregularis tetrapetali* of Riviéres, and the *leguminosae* of Ray. See BOTANY, p. 1292, and Plate LIX.