Shrubs, or annual or perennial herbs, often glandular and aromatic. Stems ± quadrangular. Lvs opposite, exstipulate, usually simple. Infl. usually of modified cymes in the axils of opposite bracts, rarely of true cymes; modified cymes forming pseudowhorls (verticels or verticillasters), and these either distant along the infl. rachis or aggregated into spikes or panicles. Fls zygomorphic, usually ☿, sometimes unisexual; bracts conspicuous or very reduced; bracteoles present or 0. Calyx usually 5-toothed or 5-lobed, 2-lipped or teeth or lobes ± equal, sometimes accrescent. Corolla tube usually well-developed; limb (4)-5-lobed, 2-lipped with upper lip 2-lobed and lower lip 3-lobed, rarely with a lower lip of 5 lobes. Stamens (2)-4, didynamous when 4, sometimes 2 reduced to staminodes, epipetalous. Ovary superior, deeply 4-lobed, of 2 divided carpels, 4-celled with 1 anatropous ovule to each cell; style 1, usually gynobasic, simple below but with 2 branches above. Fr. of 4 nutlets, sometimes 1 or more aborting. Seed non-endospermic or nearly so.