Annual or perennial herbs, undershrubs, or sometimes shrubs, with various kinds of indumentum or sometimes nearly glabrous. Leaves sessile or petiolate, entire or toothed. Inflorescences terminal or axillary, spike-like, sometimes panicled; flowers in 2-many-flowered verticils, sessile or pedicellate; bracts leaf-like or reduced; bracteoles usually present, linear. Calyx subequally 5-toothed or rarely +/- bilabiate, 5-10-nerved; teeth usually shorter than tube, ovate-acuminate to lanceolate-acuminate, sometimes ending in a short bristle-like point. Corolla bilabiate; tube straight or curved, sometimes pubescent without and usually annular-pilose near base within; upper lip erect or ascending, usually concave or arched, entire or very shortly emarginate, usually shorter than lower lip; lower lip spreading or deflexed, 3-lobed, with middle lobe the largest. Stamens 4, didynamous, ascending under the upper lip, lower pair the longer, usually shortly exserted from corolla tube; anthers 2-thecous, with thecae usually divergent and at length divaricate. Style terete, as long as stamens, equally bifid. Nutlets ovoid or oblong in outline, often triquetrous, obtuse or rounded at apex. x = 8, 9, 17 (10, 12, 15) (aneuploids, polyploidy).
Species +/- 300, mainly in subtropical and temperate regions of both hemispheres; 42 in sthn Afr., widespread.