Herbs, perennial. Stems quadrangular. Leaves opposite, basal and rosulate or all on stem. Racemes axillary, opposite, sometimes in compound racemes. Pedicel much longer than flower. Bracteoles absent. Calyx tubular, campanulate in fruit, 5-ribbed; lobes triangular, 1/3-1/2 of tube length, rib reaching lobe apex. Corolla pale purple or pale red; tube long; palate with 2 bulging plaits; limb 2-lipped; lower lip longer than upper, 3-lobed; lobes somewhat spreading, crisp, margin ciliate; lateral lobes of lower lip exserted in bud, as long as lobes of upper lip at anthesis; middle lobe orbicular, larger than other lobes, base with 2 bulging glandular hairy plaits, margin slightly recurved; upper lip erect, lobes 2 and wider than long. Stamens 4, included, didynamous; anther locules basally divaricate, apically confluent. Stigma 2-lobed. Capsule oblong, compressed, emarginate, loculicidal, placenta dilated. Seeds numerous, ellipsoid, compressed, with a transparent membrane.

* Two species: endemic to China.