Cladostemon kirki has leaves that are trifoliolate with obovate leaflets that are glabrous with a thin texture and a common petiole up to 200 mm long.
The large pendulous fruits are gourd-shaped, have a leathery texture and are up to 12 cm in diameter, hang from long, thick, sharply bent, jointed stalks, and give off an odour repulsive to humans on being picked.