in botany: A genus of the monogynia order, belonging to the decandria class of plants; and in the natural method ranking under the 30th order, Contortae. The calyx is monophyllous and quadripartite; the corolla is monopetalous, tubulated, and parted into 10 laciniæ: the fruit is an oval berry, which is grooved longitudinally, and contains many small angular seeds. Of this there is only one species, the amara, a native of Guiana. The leaves and stalks are bitter, and used by the natives as an emetic and purge.