Annual or perennial herbs, undershrubs or shrubs with various kinds of indumentum. Leaves entire, toothed, or +/- deeply lobed. Inflorescences terminal on branches, spike-like or panicled; flowers in 2-many-flowered verticils; bracts usually reduced, rarely similar to upper leaves, sometimes showy, deciduous or persistent; bracteoles usually present. Calyx 2-lipped, +/- as long as corolla tube, sometimes accrescent, variously hairy and often glandular; upper lip entire or 3-toothed, median tooth often shorter or obsolete; lower lip equally 2-toothed, longer than the upper. Corolla 2-lipped; tube straight or curved, usually enlarging towards throat, annular-pilose or exannulate within, invaginated with a plate of internal tissue or not; upper lip usually longer than lower lip, straight or falcate, usually concave and +/- compressed, entire or bifid; lower lip spreading, 3-lobed, median lobe usually much larger than the two lateral. Stamens 2, curved; connective produced and lying within upper lip and bearing an oblong or linear anther theca; other part of connective produced into a variously shaped appendage, sterile or bearing a much reduced anther theca, appendages cohering or not; staminodes 2, small and usually inconspicuous. Style included or exserted from corolla, usually exceeding stamens, unequally 2-lobed. Nutlets triquetrous to compressed, ovoid to subglobose, smooth, mucilaginous on wetting or not. x = 8, 11 (6, 7, 9, 10) (aneuploids, high polyploidy, B-chromosomes).
Species +/- 900, widely distributed in temperate and tropical regions of both hemispheres; 27 species in sthn Afr., widespread; 1 European species and 3 from tropical America have become naturalised.
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