Perennial subshrubs with erect or ascending stems, hairs 2-branched. Leaves simple, entire, sessile or shortly petiolate. Inflorescences terminal leafy spikes or heads; bracteoles present. Flowers solitary in upper leaf-axils, subsessile; sepals 5, free, subequal; corolla campanulate, 5-lobed, lobes imbricate, c. as long as the tube, pilose; stamens 5, more or less equal, exserted, filaments laterally fused at base, glabrous or tuberculate towards base; ovary partly or completely 2-celled, villous in upper half, ovules 2 per cell, styles 2, fused in lower half, stigmas capitate. Capsule ovoid, splitting longitudinally into 2–4 valves; seeds usually 1 per capsule, glabrous.
Monotypic genus widespread in tropical and warm-temperate regions of the world, including Australia.