Perennial herbs or shrubs. Leaves opposite or occasionally ternate or subopposite, usually entire or nearly so. Inflorescences usually terminal with flowers produced in 2-(or 3)-flowered verticils or in some species often solitary; flowers often scented; bracts leaf-like, becoming smaller towards apex of flowering branch. Calyx 2-lipped, becoming much enlarged, ovoid, inflated and 2-valved with maturity, often densely pubescent; lips entire, broadly rounded. Corolla 2-lipped, often liver-coloured or shades of dark reddish purple to mauve; tube short or long, cylindrical at base, widening near throat; upper lip short, broad, ascending, emarginate or 2-lobed; lower lip much larger, spreading, 3-lobed, median lobe often emarginate, larger than lateral rounded lobes. Stamens 4, slightly protruding, ascending under upper lip, pubescent near base; filaments of posterior pair thicker, crossing filaments of anterior stamens so that anthers are placed uppermost in throat, thickened above, thickened portion yellow and visible in corolla throat; anthers 2-thecous, anthers on shorter filaments smaller. Ovary divided to halfway or more; style filamentous, shortly bifid, lobes unequal. Nutlets obovoid-clavate, attached by a lateral areole occupying up to half the length, furnished on back with a broad elliptic or orbicular 'wing' made up of stiff primary rays interlaced with fine transverse hairs. x = 8 (1 report) (polyploidy).
Species 19, Africa; 4 in sthn Afr.: 2 species in the northern parts of Namibia and Botswana, 2 species from Northern Province, Mpumalanga, Swaziland and KwaZulu-Natal.