Gomphocarpus physocarpus is a species of flowering plant in the Milkweed subfamily, Asclepiadoideae, and Dogbane Family Apocynaceae. It is commonly known as hairy balls, balloonplant, balloon cotton-bush, bishop's balls, nailhead, or swan plant. The plant is native to southeast Africa, but it has been widely naturalised as it is often used as an ornamental plant.
