A dicotyledonous (see dicotyledon) family of herbs with tuberous roots that are known as unicorn plants because of their horned fruits. Characteristically, the plants are covered in sticky hairs, and have simple, opposite or alternate leaves and no stipules. The terminal inflorescence is composed usually of showy flowers which are 2-lipped. The corolla is cylindrical, or funnel- or bell-shaped, and the stamens are attached. The ovary is superior with a basal nectary disc, 2 fused carpels, and 1 locule. There is a single style and a forked stigma which is sensitive to touch. The fruit is a capsule, with the persistent style forming a horn or a hooked projection which is a useful aid to dispersal by animals. The seeds are compressed, with a straight embryo and no endosperm. Some species are cultivated for their unusually shaped fruits, which can be pickled and eaten. The family is related to the Bignoniaceae. There are 3 genera, with 13 species, found mainly in tropical and subtropical America.
Subjects: Plant Sciences and Forestry.