Ground-nut, GROUND-BEAN, or PEA-NUT, the fruit of Arachis hypogæa, an annual plant belonging to the natural order Leguminosæ, extensively cultivated in southern North America, but supposed to be a native of Africa. The name Arachis, Aracos, or Aracidna, was given by Pliny to a plant which was stemless and leafless, being all root. Modern botanists have given the name to a species which ripens its fruit underground. The pods, though first formed in the air, are as they increase in size forced into the earth by a natural motion of their stalks, and there come to maturity 3 or 4 inches under the surface, hence the popular name Ground- or Earth-nut. In the southern states of North America the seeds, or nuts, as they are called, are roasted and used as chocolate. When fresh they have a sweet taste resembling almonds. They are a favourite article of food with the negroes. A fixed very sweet oil is extracted from the seeds, which is considered by some equal to olive-oil, and it does not become rancid, rather improving with age. Ground-nuts are to be met with occasionally in fruiterers' shops in Britain, and some attempt has been made to cultivate the plant around Paris; but requiring as it does to be reared in hot-beds, expense and trouble have circumscribed its adoption as a commercial production there. It is, however, cultivated in some of the warmer countries of the south of Europe.—The roots of Bunium bulbocastanum and B. flexuosum are also known as ground-nuts or Earth-nuts (q.v.).