These seeds arrived in the post today from Owen of Radix. His blog is the most entertaining one I know of. Also known as the American Hog Peanut, Amphicarpaea bracteata is native to eastern North America and was a popular food of native Americans. It can reproduce either by flowers which open and are pollinated, or by cleistogamous flowers (which develop into seeds without opening, following self-pollination). The cleistogamous flowers can be above ground or below ground. The seed pods are both above and below ground. It will be interesting to see how they do here. I would love them to naturalise in the woods. I have potted them up in the polytunnel and will pamper them this year.