Properties
The American groundnut (Apios Americana), or hopniss, is a climbing perennial plant from the woodland edges of North America. It’s related to the peanut and produces new shoots each year from numerous underground tubers, these new shoots twining around any supports they can find.
The tubers were a staple food among many Native American groups within the natural range of the plant. In 1749, the travelling Swedish botanist Peter Kalm writes:
“Hopniss or Hapniss was the Indian name of a wild plant, which they ate at that time… The roots resemble potatoes, and were boiled by the Indians who ate them instead of bread.”
Also, as Hank Shaw of honest-food.net notes, “The American groundnut was an important factor in the survival of the Pilgrims during the first few winters of their settlement.” In 1623 the Pilgrims, “having but a small quantity of corn left,” were “enforced to live on groundnuts… and such other things that the country afforded… and were easily gotten…”.

American groundnut flowers. Photo: Wikimedia Commons
Where It Grows
Its natural range is from Southern Canada (including Ontario, Quebec, and New Brunswick) down through Florida and West as far as the border of Colorado.
One of the earliest, if not the first, European references to the american groundnut is from Sir Walter Raleigh’s 1585 voyage to Virginia. His resident scientist, Thomas Harriot, wrote a report about all the potentially useful things he encountered during the voyage in the New World, including:
Openauk, a kind of root of round form, some of the bigness of walnuts, some far greater, which are found in moist & marish grounds growing many together one by another in ropes, or as though they were fastened with a string. Being boiled or sodden they are very good meat…
The plant prefers light dappled shade in its native environment, and can be grown along the sunny edges of a woodland garden. It dislikes windy situations.

Groundnut foliage. Photo: http://extension.umass.edu/landscape/sites/landscape/files/weeds/leaves/apoam6228w.jpg
Why We Like It
- The edible tubers have a very pleasant sweet taste when baked, and contain roughly three times the protein content of a potato (16.5% by dry weight).
- The tubers are also an excellent source of calcium and iron. Calcium content is 10-fold greater than a potato and iron is 2-fold greater than a potato, although vitamin C was considerably less than a potato.
- Will keep a month or more in the fridge or root cellar, or dry them and they keep forever. Some native american tribes also boiled them in maple syrup to preserve them.
- It’s a very easy plant to grow, preferring a light rich soil and a sunny position.
- The plants will be long lived with the tuberous roots increasing in size and number each year.
- The groundnut is also said to be very tolerant of acid soils.
- It helps to enrich the soil with nitrogen by means of bacteria which live on the roots and fix atmospheric nitrogen. This makes it a very good companion plant in a forest garden, and gives it an advantage over potatoes, true yams, sweet potatoes, etc., that don’t have this ability and thus require nitrogen fertilizer inputs.
- Wild plants can produce yields of a kilo or more of tubers per plant so long as they are left to grow for 2 years before harvesting them. Cultivated plants can produce an even larger yield.
- The tubers can be dried and ground into a powder then used as a sweetener and thickener in soups or can be added to flour.
- It has been shown that the tubers contain genistein and other isoflavones that have various health benefits, including an anticarcinogenic function against colon, prostate, and breast cancer.
Where To Get It
The American Groundnut can be grown from seed or by planting the tubers, and you’ll more often find small tubers for sale rather than seeds.
United States
Fedco Seeds (Ordering will resume in early October 2015)
Norton Naturals
Sand Mountain Herbs (available November – May annually)
Europe
Learn More / References
Plants for a Future
Wikipedia
Temperate Climate Permaculture
Honest-Food.net
Featured photo: http://chenocetah.files.wordpress.com/2007/11/apiostubers2.jpg