Plant Form Perennial clump-forming herb. Size Up to 1.5 m tall. Stem Thick green fleshy and sappy stalks 80 cm long, winged at base. Leaves Large, arrowhead shaped, glossy, dark green, up to 60 cm long. Flowers Typical arum, central yellow spike (spadix) surrounded by large white leaf-like petal (spathe) up to 25 cm long. Fruit and Seeds Irregular globular berries, 5-10 mm wide, in clusters at base of central spike. Containing several to many small yellowish brown seeds. Habitat Marshy areas, wasteland, rubbish dumps, wetlands, creeklines. Distinguishing Features With flowers it can be distinguished from Italian arum (Arum italicum) by its larger size. Without flowers it is hard to distinguish from several other cultivated plants. Impacts Replaces pasture species, dominates and shades out natives, toxic to humans and livestock.