Suffrutescent perennial herbs or shrubs. Leaves simple, petiolate, lineolate, usually entire. Flowers blue, purple, violet or purplish-white in terminal or axillary, simple or branched dense spikes; bracts large, longer than the calyx, neither ciliate nor spinescent, bracteoles smaller than sepals. Calyx deeply 5lobed, lobes equal, valvate, almost scarious. Corolla tube cylindrical, more than twice as long as ± equal patent limb lobes, imbricate. Stamens 4, inserted at the throat, 2 fertile with dithecous, parallel, emucronate anthers, staminodes 2, small, shortly connate to filaments. Ovary bilocular, each locule 2-ovuled; style long, ± hairy. Fruit an oblong-clavate, 4-seeded capsule with solid dips-like basal part. Seeds mucilaginous hairy, supported on retinacula.