The genus Colocasia includes six species of tuberous perennials from tropical Asia, grown there as a staple food. They are native to swamps and other moist areas and can be used in large aquatic containers in the garden or in the ground in moist soil. The arrow-shaped, sometimes rounded, leaves are large and mostly green, sometimes with prominent veins. Cultivated plants rarely bloom. All plant parts may cause stomach upset if eaten raw, and the sap may irritate skin.