Herbs, perennial or suffrutescent, rarely annual. Leaves opposite or rarely upper ones alternate. Cymes axillary or terminal and solitary, or inflorescences lateral thyrses, racemose, spicate, or subcapitate, usually pedunculate. Calyx 5-lobed. Corolla usually 2-lipped; lower lip shorter than upper lip, 3-lobed, middle lobe flattened forward, lateral lobes suberect; upper lip 2-lobed, lobes suberect. Stamens 4, somewhat didynamous, included to exserted, adnate to corolla tube; anther locules confluent; staminode 1, small. Disc present. Style as long as or longer than ovary, slightly shorter in S. urticifolia; stigma often small. Capsule septicidal. Seeds numerous.

About 200 species: temperate Asia, Europe (mostly Mediterranean), North America; 36 species in China.