The Benefits Of Water Yam For Health. Water yam is the tuber of Dioscorea alata and is also called wild yam. It is different from most other yams because it is mucilaginous and so, it is not as popular for cooking. It is used by Yoruba people to make delicacies like ikokore (water yam porridge) and ojojo (fried grated water yam balls). Water yam is called ewura in Yoruba.