Erect perennial or annual herbs. Leaves opposite or verticillate. Cymes umbellate. Flowers coloured. Calyx 5-lobed, usually with 5-10 glandular structures at the base of the sinuses. Corolla reflex-rotate, 5-lobed. Corona usually of 5 stipitate tubular segments (hoods) attached to the top of gynostegium stipe; from within each of the hoods a horn arises which arches over the gynostegium. Anthers terminated by an inflexed membrane; pollinia oblong, 2 per anther, pendulous in the anther thecae. Stigma flattened, 5-angled or lobed. Follicles acuminate. Seeds comose.