This vine has heart shaped leaves. I have only seen this at Connestee Park (conesteepark.com) as an udergrowth plant. The young leaves are almost golden. It is very prolific in this one area.
this is a very invasive plant, the Chinese Yam, Dioscorea oppositifolia – aka Dioscorea batatas. It is introduced and does not behave as nicely as our native species of Dioscorea. Some states declare it to be a noxious weed, I’m afraid. There are more details about the plant here: http://en.wikipedia.org/wiki/Dioscorea_opposita It is also called the Air potato. http://plants.usda.gov/java/profile?symbol=diop http://www.ppws.vt.edu/scott/weed_id/diuba.htm
It does have its uses, as a google search will tell you.
I hope this helps!
Steve Hill (Ph.D.) SCNPS