in botany: A genus of the monogynia order, belonging to the decandria class of plants; and in the natural method ranking under the 33rd order, Lomentaceae. The calyx is semi-quintefid; the corolla has five petals, which are equal; the tube is turbinated, carious, and persistent. The legumen pedicellated, and contains two seeds; there is only one species, viz. the speciosa, or African lignum vitae.