The scientific name for American Groundnut is Apios americana and it is also popularly known as Indian potato, hopniss and potato bean. This vine which is perennial grows all over the eastern part of North America. The area of its growth covers the whole belt from Ontario to Quebec on the northern part and extends right up to the Gulf of Mexico. On the western side it extends right from the prairie lands, up to the Atlantic coast. This vine is mainly found along rivers and in the forest shrubbery.
The American Groundnut is a perennial vine which can grow up to 4 meters. It usually climbs on to any support it finds and the vines are slender. It will grow through the shrubbery also and is many times mistaken to be poison ivy. New shoots will keep appearing at regular intervals, from the many tubers underground. There are multiple stems which grow underground, just about 2 to 3 inches from the surface of the soil. These stems have swollen nodes at regular intervals, measuring about 2 inches in diameter. The leaves are smooth and dark green in color and are compound pinnate, measuring 8 to 15 cms in length. There will be about 5 to 7 pointed leaflets forming a tapering pattern, with the larger leaflets on opposite sides at the base and culminating with a single leaflet at the top.
Flowers and Fruits
The flowers are fragrant and reddish brown to purple in color. They grow in clusters and are quite attractive. The fruit is the legume pod which will grow from the flowers. The length of the pod will vary between 6 to 12 cms.
Although a wild plant it has excellent food value. The tubers are and excellent source of starch and protein. These tubers can be cooked and can also be eaten raw. They are chewy and starchy when eaten raw, and when cooked they have a soft texture which feels floury, having a hint of sweetness. These groundnut tubers are known to have thrice the amount of proteins contained in potatoes, if you compare the same amount of both in dry weight. The tubers can also be dried and powdered, and this powder can be used as a thickener for soups and also as a nutritious additive to flour. The plant as a whole is very beneficial for the soil as it fixates nitrogen, and other plants growing nearby can benefit from it. There are certain bacteria in the soil, which form on the roots, small nodules, and fix the nitrogen from the atmosphere.
American Groundnut is easy to propagate by dividing the tubers in spring or autumn. The tubers can be planted immediately or can be stored in a place which is without any frost. The stored tubers have to be kept moist as total drying will make them wither away. Propagation by seed is also possible, and quite easy. The seeds need to be soaked in water which is not cold for at least for 5 hours. Once they are swollen to double their size, they can be sowed. Germination usually takes between one to three months depending on the temperature, which ideally should be 15 degrees