|Abstract||Annual or perennial, unarmed or spinous, bitter herbs or undershrubs, often glandular-hairy. Stem terete, farctate, with a peripheral whorl of air-vessels. Leaves spread, simple, entire, exstipulate. Flowers ♀, actinomorphic, solitary, opposite or between the leaves, or by stunting of the leaves, more or less arranged in a racemiform or paniculiform inflorescence, distinctly pedicelled, lilac blue. Calyx persistent, 5-partite to near the base, segments lanceolate, imbricate in bud, after anthesis not or hardly accrescent. Corolla gamopetalous, deeply 5-partite; limb rotate; segments imbricate in bud, oval, obtuse. Stamens 5, free, inserted in the throat of the corolla, alternating with the segments; filaments filiform from a broadened base, glabrous or papillate; anthers 2-celled, bifid at the base and apex, opening lengthwise. Disk absent. Ovary superior, 2- (rarely 3-, very rarely more-) celled; placentas adnate to the dissepiment, spongy, entire or in cross-section bifid; styles 2 (rarely 3 or more), free; stigmas capitate-clavate. Ovules ~. Capsule globose or ellipsoid, loculicid, or both loculicid and septicid, 2(rarely more)-valved, or bursting irregularly. Seeds ~, very small, longitudinally ribbed; endosperm small, straight.|
Distr. Species ± 20, in the tropics of both hemispheres; in Malaysia 2, of which one indigenous, the other introduced and naturalized in Java.