Herbs or shrubs. Leaves opposite or whorled. Flowers zygomorphic, solitary or borne in clusters or racemes. Calyx tube elongated and corolla-like, ribbed, spurred or gibbous at the base, oblique at mouth with 6 primary teeth or lobes and usually as many secondary teeth. Petals 6 (rarely 0 or 2). Stamens 11, rarely fewer. Ovary usually superior, sessile with a gland at the base, unequally 2-locular. Stigma capitate, 2-lobed. Capsule oblong, papery, dehiscing laterally.