From:Nashville, IN Region: Midwest Topic: Non-Natives Title: Non-native, invasive, poisonous Chinese yam Answered by: Nan Hampton and Joe Marcus
I found a vine in my yard [central Indiana] which I believe is Dioscorea oppositiflora and I wanted first to confirm my identification and second to find out about edibility [especially of the airborne tubers] and uses.
It has single and paired tiny potato like tubers in the leaf axils. the leaves are deeply veined and a deep lobed elongated heart shape. It is fall and I have not observed the inflorescence.
Apparently there are several species [subspecies?] of Dioscorea?
Chinese yam or Cinnamon vine (Dioscorea oppositiflora, syn. D. batatas) is a non-native vine introduced from China into North America as an ornamental. Both the tubers and the bulbils (the tuber-like growths in the leaf axils) are edible if cooked. However, the Poisonous Plants of North Carolina database lists the uncooked tuber as toxic. Your description doesn't conflict with that of D. oppositiflora, but we can't absolutely identify a species by description alone. Certainly, we wouldn't want to try doing this if it is something you intend to eat. Note of caution: Get a positive identification of your plant before you eat it!
Although it is attractive, D. oppositifolia (along with two other members of the Genus Dioscorea, D. alata and D. bulbifera) is a fast growing and aggressive vine that is considered an invasive weed in the southeastern United States. For an extensive discussion of the biology, uses, invasiveness, and control measures for D. oppositifolia see this article from The Nature Conservancy.
More Non-Natives Questions
Absence of blooms in non-native Rosa rugosa June 30, 2008 - I have a rosa rugosa in my yard that was here when I moved in..and it has never bloomed. It is in a sunny spot, but there are never any flowers..not even a single bud on this trailing plant. I cut it ... view the full question and answer
Diamonds and Rubies plant (Lychnis coronaria) May 02, 2007 - I recently purchased a plant from the Huntsville, AL Botanical Gardens at their annual plant sale. The name on the plant tag is "Rubies and Diamonds". No one at the Botanical Garden knew the scien... view the full question and answer
Replacing non-native Paulonia tomentosa in North Carolina June 25, 2009 - What could I plant in my Winston-Salem, N.C., yard in place of the paulownia tomentosa which is there now (it was NOT something I put there; I only figured out what it was a couple of years ago -- I g... view the full question and answer
Non-native chocolate mimosa in Levittown NY August 09, 2010 - I purchased about 2 ft chocolate mimosa tree in early June of this year from a local nursery located in Nassau County, New York. It was doing in our Long Island soil just fine for over a month, I woul... view the full question and answer