Apocynaceae

Trees, shrubs, lianas or rarely herbs, often with milky or viscid sap. Leaves opposite or sometimes verticillate or alternate, simple and always entire, penninerved. Stipules minute or mostly wanting. Flowers actinomorphic, hermaphrodite, arranged in racemose or cymose inflorescences or solitary. Calyx gamosepalous, 5-lobed, imbricate, often bearing glands (squamellae) within. Corolla gamepetalous, usually salver-shaped or funnelform, the tube occasionally bearing more or less conspicuous faucal appendages within (corona), the limb 5-parted, the lobes usually contorted in aestivation. Stamens (4—)5, inserted in the corolla-tube, alternating with the corolla-lobes; filaments usually short; anthers 4-celled, introrse, often sagittate and apiculate with the connective produced, free or coherent around the stigma. Pollen granular or in tetrads. Ovary superior or sometimes half-inferior, 2-carpellary, 1-locular with parietal placentation or 2-locular with axile placenta or apocarpous and then connected basally and by the style; style 1, split at the base or entire, thickened below the apex; stigma massive, variable in form. Disk often present. Ovules few to many, usually anatropous. Fruit of solitary or paired follicles or a capsule, berry or drupe. Seeds comose or with a papery wing. Embryo large, straight. Endosperm present. About 2000 species in 200 genera, mostly in the tropics and subtropics and only a few species in temperate regions.