Fls axillary, ± pilose to glab., solitary or occ. racemed. Calyx sub-campanulate, 5-angled, 5-lobed. Corolla with long tube terminating in 2-lipped limb; upper lip 2-lobed, erect to patent; lower 3-lobed, throat us. with 2 protuberances. Stamens 4, didynamous, anther-cells divergent, often confluent at apex. Style slender, stigma 2-lamellate. Capsule 2-valved, loculicidally dehiscent. Herbs with opp. simple, entire or toothed lvs. Some 120 spp. of America, Asia, Africa, Australia, Tasmania, N.Z. The N.Z. sp. also in Tasmania.

Annual or perennial herbs or small shrubs, often glandular-hairy, sometimes glabrous. Lvs opposite, entire or toothed. Fls usually solitary, axillary, occasionally in terminal racemes. Calyx tubular, 5-angled and equally or unequally 5-toothed or 5-lobed. Corolla somewhat irregular to strongly 2-lipped; tube cylindric to funnelform; upper lip 2-lobed, reflexed or erect; lower lip of 3 spreading lobes; throat open or closed by a pouch. Stamens 4, included. Fr. a loculicidal capsule dehiscing on 1 or both sides. Seeds numerous, patterned, very small; wing 0.