Family: Fabaceae (Legume family)
Height: up to 1.5 m (up to 5 ft)
Blooming: July - Sept.
Amphicarpaea bracteata (L.) Fern.
Stems: twining or sprawling. It can have hair or be hairless or densely hairy.
Flowers: two forms of flowering are present - one is that highlighted in all of these pictures and appears above ground while the other is near the ground to subterranean. The above ground flower's corolla is white, light purplish, soft pink or a mix of the three. The calyx is greenish white to almost completely white. The calyx can have hair on it. The flower near the ground is produced on the stolon (stem creeping along the ground), cleistogamous (not opened for pollinators) and self-pollinates creating a single, edible seed.
Leaves: alternately arranged with 3 stalked leaflets (trifoliate). Leaves can be pubescent or glabrous. The leaflets are rounded at the base and 2-10 cm (0.75-4 in) long.
Fruits: legume that is straight and brown reaching 1.4-4 cm (0.5-1.6 in) long. The underground or near-surface fruit is large and fleshy.
Comments: Hog peanut is a variable species when it comes to the amount of hair and leaf size of the individual plant. Three varieties have been fleshed out based on a bunch of characteristics. Without fruit, hog peanut can often look like groundnut (Apios americana), but groundnut usually has more than three leaves (five to seven). Hog peanut also has the large, fleshy subterranean fruit while groundnut has large tubers.
Hog peanut's large, fleshy subterranean fruit was used by many Native American tribes as a food.
Etymology: The genus, Amphicarpaea, comes from the Greek word meaning "two fruits" due to its different fruits. The epithet, bracteata, means "small leaf" not for its leaves but rather for the small leaf-like bracts opposite of the flowers.
SOURCES & FURTHER RESOURCES:
Great Plains Flora Association. 1986. Flora of the Great Plains. University Press of Kansas, Lawrence, KS. pp. 420.
Kindscher, K. 1987. Edible wild plants of the prairie: an ethnobotanical guide. University Press of Kansas, Lawrence, KS. pp. 37-42.