Apios americana Medik.
Apios americana Medik. var. turrigera Fernald
Glycine apios L.
Potato Bean, Groundnut, Hopniss, Indian Potato, Bog Potato, Virginia Potato, Wild Potato, Wild Sweet Potato
Potato beans are natives of eastern North America. Its edible beans and roots were an essential food for native Americans and European settlers alike, attested to by its many common names. They are members of the legume family, and like other legumes, their roots have a bacteria that traps nitrogen.
Identification: Potato beans are vines that reach 9½-13' (3-4 m) in length. Leaves are 3-6" (8-15 cm) long, with clusters of 5-7 leaflets. Flowers are in dense, rounded clusters, red-brown to purplish in color, ⅜-½" (9.5-12 mm) in size, shaped similarly to other pea family flowers, but uniquely colored. The flowers have a spring-loaded pollen distri­bution system that is triggered by insects. Bean pods are 2-4" (5-10 cm) long and about ¼" (6.3 mm) in diameter.
Edibility: The beans from this plant are edible, as well as the tubers (roots), which are crunchy, and contain starch and 2-3 times the protein of potatoes. Long underground roots have nodules or swellings that are the tubers, which may be prepared like potatoes. Peeling is not necessary. Henry David Thoreau preferred his potato beans boiled rather than roasted; they can also be fried. When boiled, the roots taste like a cross between boiled peanuts and somewhat granular or powdery potatoes. They are a good choice for chips, since their reduced sugar content keeps them from browning. They can be added to salads, soups, stews, or vegetable dishes. Poison ivy is sometimes found growing near this plant, so be careful not to harvest (or even touch) any poison ivy roots, which are just as toxic as the rest of the plant.
Curiously, this historically important food is only now being developed as a commercial crop. Groundnut is listed as an obvious candidate for this purpose in North American Cornucopia: Top 100 Indigenous Food Plants.
Medical: A few people are allergic to groundnut.
Apios americana on Missouriplants.com
Apios americana on hort.purdue.edu (an article about the domestication of Apios americana from Purdue University)
Apios americana on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Apios americana in Orion Magazine (an article entitled Stalking the Wild Groundnut)
Apios americana description by Thomas H. Kent, last updated 2 Jan 2019.