Tannia, scientifically known as Xanthosoma sagittifolium, is a tropical plant that belongs to the Araceae family. It grows edible, starchy corms underground. Tannia is originally from tropical America, where it was first grown. In the 19th century, people started growing it in Southeast Asia and Africa too. Tannia is often mixed up with another plant called Taro, scientifically known as Colocasia esculenta, because they look alike and are used in similar ways. Both of these plants are sometimes called Cocoyam together.