The family Apocynaceae consists of tropical trees, shrubs and vines. Characteristic features of the family are that almost all species produce milky sap. Leaves are simple, opposite or whorled; lowers are large, colourful and slightly fragrant with five contorted lobes; and fruits are in pairs. With the inclusion of species of Asclepiadaceae, the family has now enlarged from two to ive sub-families. The expanded family now comprises more than 150 genera and 2000 species.