What is "earth chestnut"

Groundnut \Ground"nut`\ (ground"n[u^]t`), n. (Bot.)

1. The fruit of the Arachis hypog[ae]a (native country uncertain); the peanut; the earthnut.

2. A leguminous, twining plant ( Apios tuberosa), producing clusters of dark purple flowers and having a root tuberous and pleasant to the taste.

3. The dwarf ginseng ( Aralia trifolia). [U. S.]
   --Gray.

4. A European plant of the genus Bunium ( B. flexuosum), having an edible root of a globular shape and sweet, aromatic taste; -- called also earthnut, earth chestnut, hawknut, and pignut.

Earth chestnut is a common name for several plants and may refer to:

• Bunium bulbocastanum
• Conopodium majus