purple yam

An edible tuber or root vegetable of a plant, with the botanical names Dioscorea alata and Dioscorea rubella, which in Vietnam is mashed, cooked and used in a type of soup, while in the Philippines, it is eaten as a sweetened jam. The tuberous root is also used as a vegetable, as well as an ingredient in other food, especially in desserts, such as ice cream and pastries. Whilst on the outside this tuberous root is a dark greyish-brown to near black, on the inside it is whitish with purple. 回