Amphicarpaea bracteata aka Hog Peanut

Amphicarpaea bracteata is a climbing plant in the pea family, Fabaceae. Its common names include hog peanut and American hogpeanut. Its native range spans central and eastern Canada and the United States. It also grows in Veracruz and Puebla in Mexico. Its habitat includes cool, damp woods within temperate regions. It is not native to Britain or Ireland.

The stems climb to about 5 feet [1.5 metres]. Sources differ on its life cycle. Kew lists a climbing annual, while Plants For A Future describes a perennial. That source records leaves from May through October. It also notes a small taproot. New shoots can suffer damage from late spring frosts. This can occur despite the plant's stated winter hardiness.

Flowers appear from August to September, with seeds ripening in September and October. The plant makes two kinds of flowers. Flowers in the leaf axils mostly fail to set seed. Some still form pods above ground. Small, closed flowers grow near the root on thin stems. These cleistogamous flowers form pods that push beneath the soil. Each buried pod holds one seed. Plants For A Future also lists insects as pollinators. Its flowers contain both male and female organs.

Grow hog peanut in moist soil rich in humus. Plants For A Future recommends a shady site. It lists both full and partial shade as suitable. Sandy, loamy and clay soils can support it. It also accepts mildly acid, neutral and mildly alkaline soil. The listed USDA hardiness range is zones 4–9. Its shade tolerance suits woodland beds and food forests. It fixes nitrogen, giving it a role as an understory legume.

People have grown hog peanut for its edible seeds. The buried seeds can serve as a peanut substitute. They can be eaten raw or cooked and gathered through winter. Their raw taste resembles shelled garden beans more than peanuts. Yields are low, and finding the buried crop takes work. Plants For A Future also lists the root as edible. It records past medicinal uses of roots and leaves. These records do not establish safety or effectiveness as treatments. The source reports no known hazards, but provides no pet-safety assessment. It reports no weed potential and gives no specific pest or disease problems.