Family Apocynaceae, of the gentian order, with about 1,000 member species of trees, shrubs, woody vines, and herbaceous plants, found mostly in the tropics and subtropics.
Dogbanes have milky, often poisonous juice and usually clustered, showy flowers. Garden ornamentals include periwinkle , oleander , yellow oleander ( Thevetia ), frangipani , Natal plum ( Carissa ), and crepe jasmine ( Tabernaemontana coronaria ). Some species are African succulents . Arrow poisons are obtained from many dogbanes, and the poisonous alkaloids of some species are used in medicines.