Herbs, shrubs or sometimes climbers. Stipules 0. Leaves opposite, usually entire, less often toothed. Flowers bisexual, actinomorphic or zygomorphic. Bracts and bracteoles usually present. Calyx 4-5-partite, rarely 2-lipped or with 10-18 teeth (Thunbergia). Corolla gamopetalous, 1-2-lipped or 5-lobed. Stamens 2 or 4, inserted on corolla. Anthers 1- or 2-thecous, with thecae together or one above the other. Ovary superior, 2-locular with (1-)2(-3 or more) ovules in each loculus. Fruit a loculicidal capsule, often explosively dehiscent.