Herbs or shrubs. Flowers large, scarlet or
yellow, whorls axillary, densely many-flowered, bracteoles numerous, slender.
Sepals connate in a 10-nerved calyx, tube often incurved, mouth oblique, with
8-10 rigid teeth, upper tooth largest. Petals 5, connate in a 2-lipped corolla,
tube exserted, upper lip long, concave with villous crown, lower very small,
spreading, concave, mid-lobe largest. Stamens 4, didynamous, lower pair longer,
ascending, anthers connivent, disk equal. Carpels connate in a 4-partite ovary,
styles subulate, upper lobes very short. Fruit glabrous nutlet, oblong or
ovoid, dry, triquetrous, obtuse or truncate, basal scar small.