Amorphophallus (from Ancient Greek amorphos, "without form, misshapen" + phallos, "penis", referring to the shape of the prominent spadix) is a large genus of some 170 tropical and subtropical tuberous herbaceous plants from the Arum family (Araceae).

These are typical lowland plants, growing in the tropical and subtropical zones of the paleotropics, from West Africa to the Pacific Islands. None of them are found in the Americas although a remarkably similar but not closely related genus, Dracontium, has evolved there. Most species are endemic. They grow preferentially on disturbed grounds, such as secondary forests.

These small to massive plants grow from a subterranean tuber. From the top of this tuber a single leaf, which can be several metres across in larger species, is produced atop a trunk like petiole followed, on maturity, by a single inflorescence. This leaf consists of a vertical leaf stalk and a horizontal blade, which may consist of a number of small leaflets. The leaf lasts one growing season. The peduncle (the primary flower stalk) can be long or short.