Plant · P-023

Groundnut

Apios americana

American groundnut is a twining perennial legume grown for a string of tubers threaded along its rhizome like beads on a necklace. The tubers taste something like roasted sweet potato and carry roughly three times the protein of a potato, making it one of the few perennial root crops that works as a protein staple rather than a starch. It fixes its own nitrogen and shares some with neighbouring plants, but it needs a fence, shrub or trellis to climb and takes two to three years in the ground before the tubers size up. Any tuber left behind resprouts the following spring, so once established it is best treated as a permanent patch rather than a bed cleared and replanted each year.