This is the leaf of Dioscorea japonica (japanese yam) which i got from a friend in Penang. Every year, near chinese new year she would obtain a few of the root from a relative and use it to cook a desert similar to Cheng T'ng. The root would be washed, skinned and sliced. Only one leaf is shown cos i just re-planted the vine into the pot after digging up the yam for cooking.
Left: This is the root that i dug up from my pot after planting for a year.
Below: Another view of the root.