Calyx subtended by pseudo-involucre of scalelike bractlets; corolla campanulate to rotate; stamens us. nearly equal. Ovary imperfectly 4-locular, with free-central ± 4-winged placenta. Ovules 4, ortho-tropous, pend. Capsule 2-valved, 1-seeded. Littoral shrubs or small trees with opp. entire lvs. Family of 1 genus with several spp., mainly of tropical and subtropical coasts.

Mainly herbs, sometimes shrubs or vines. Lvs opposite, simple, exstipulate, often with cystoliths. Fls mostly in spikes, racemes, or dense heads (glomerules), occasionally solitary. Bracts often conspicuous and coloured. Calyx 4-5-lobed; lobes imbricate or valvate, occasionally much reduced. Corolla gamopetalous, zygomorphic, (1)-2-lipped; lobes convolute or imbricate in bud. Stamens 4 and didynamous, or 2, inserted on corolla. Ovary superior, sessile on a disc, 2-locular; ovules 2 or more per loculus. Fr. a capsule, mainly dehiscing from apex downwards; valves recurved and parting from central axis. Seeds mostly with indurated funicles which forcibly eject the seeds, usually non-endospermic.