Hey anybody ever grow dioscorea polystachya or know much about yams in general? I live in central tennessee and discovered these growing wild in one of my fields. As these are the only cold hardy yams I'm aware of I was wondering if anyone has experimented with trying to improve them. Specifically, I am interested in developing larger bulbils.
In Cornucopia 2 there is another hardy one, though there might have been a name change so it might be the same one you have found.
Dioscorea opposita - Cinnamon Vine, Chinese yam, Naga-imo, Wai shan. The tubers resemble D japonica. Eaten boiled, baked, fried, mashed, grated and added to soups, or mixed with vinegar. Often combined in tonic soups with Lycium barbarum and Polygonatum odoratum. A starch derived from the tubers is called Guiana arrowroot. Hardy as far north as Canada.
The others described are all grown in the tropics except for D trifida from the Caribbean (which I would consider tropical, but perhaps not). It is the one that sounds the most desirable - "unusual rich flavour that is readily appreciated and sufficiently moist in the mouth"
Victoria, British Columbia, Canada a cool mediterranean climate - rainy winter, dry summer