The best-known taro dish is poi, the mucous Polynesian mush made from the plant's tuberous rhizome and universally detested by tourists at staged luaus. The taro behind this gastronomic nightmare is known, in myriad species and cultivars, throughout warm parts of the Old world, from Pacific Asia to Africa. The genus is Colocasia. Its leaves are similar to spinach and are most frequently encountered in the Caribbean soup called calalu. These cause severe, long-lasting pain if ingested when the root is raw.
Cooking removes the danger.
Colocasia had reached West Africa and established itself in local diets long before 1492. The complicate matters further, there already was another edible aroid under cultivation in the Caribbean before 1492. Some forty species of Xanthosoma go by the vernacular names of tania, tannier, malanga amarilla, yautia, and cocoyam. The nomenclatural overlap with vernacular names for Colocasia makes identification especially difficult for the neophyte. Fortunately, most North American retail sources, which are usually Hispanic, deal in two fairly distinguishable varieties.