Allamanda cathartica, Plants of the genus are evergreen trees, shrubs, or vines.[citation needed] They contain a white latex. The leaves are opposite or arranged in whorls of up to 5. The blades are generally oval and smooth-edged, and some are leathery or lightly hairy. The inflorescence is a compound cyme.

The flower has five lobed sepals and a bell- or funnel-shaped corolla of five petals, yellow in most species. The fruit is a schizocarp containing two to four seeds. It does not twine, nor does it have tendrils or aerial roots. It can be pruned into a shrub form. If not pruned it can sprawl to a height of 20 feet.