1 tuber like in the picture

The fleshy tubers of common ground-nut, a twining vine, were an important food for Native Americans, and the plant has been researched for agricultural use as a food crop. There are small extra-floral nectaries on the inflorescence that are visited by ants.

Apios Americana of the family Fabaceae, is a perennial nitrogen fixing leguminous vine with edible tubers, shoots, and flowers.  The periodic swellings, or groundnuts, along the root system are available for harvest year round and can range anywhere from the size of a marble to a golf ball.  The groundnut thrives in moist, sandy soil with a pH range of 4.5-7, accompanied with full to partial sun (perfect for the edible forest garden).  The vines may need to be trellised to prevent out of control weed-like spreading; however once established, the groundnut requires little to no care. 

the value of different nutrients in 100 grams groundnut.

Calcium 93 mg

Carbohydrate 16.13 gm

Copper 11.44 mg

Fat 49.24 g

Fiber 8.5 gm

Iron 4.58 mg

Magnesium 168 mg

Manganese 1.934 mg

Phosphorus 376 mg

Potassium 705 mg

Protein 25.80 gm

Sodium 18 mg

Water 6.50 gm

Zinc 3.27 mg

Groundnut is a healthy snack. This healthy snack is grown in different parts of the world.