Species of this Genus

Herbs or undershrubs. Leaves opposite, usually petiolate. Inflorescence in simple spike or panicled, slender or stout, terete or secund. Bracts small, linear to lanceolate. Calyx ovoid or campanulate, 5-toothed, teeth unequal and often enlarged in fruits. Corolla tube shortly exserted, straight or incurved, limb 4 or 5-lobed, obliquely 2-lipped, upper lip erect and notched, lower lip spreading, 3-lobed. Stamens 4, divergent or distant, slightly unequal, filaments glabrous, anthers 2-celled, cells divaricate. Disk produced behind ovary, oblique. Styles subequally 2-fid with subulate lobes. Nutlets minute, ovoid, smooth or tuberculate.