glycine tubereuse

Apios americana, syn. A. tuberosa (Fabaceae), the American groundnut, is a perennial vine native to eastern North America, where Native Americans traditionally grew it for its protein-rich edible tubers. Its twining stems bear compound foliage and, in summer, clusters of fragrant maroon-brown flowers. The rhizome produces a string of tubers that are harvested in autumn, with a flavour reminiscent of chestnut. Grow in full sun or part shade, in cool, deep soil, with support to train the climbing growth.