The mongongo tree, mongongo nut, or manketti tree (Schinziophyton rautanenii) is a member of the family Euphorbiaceae and the monotypic genus Schinziophyton. A large, spreading tree, the mongongo, reaches 15–20 meters tall. It is found on wooded hills and among dunes and is associated with the Kalahari sand soil types. The leaves are a distinctive hand-shape, and the pale yellow wood is similar in characteristics to balsa, both lightweight and strong. The yellowish flowers occur in slender, loose sprays. The fruit is known as mongongo fruit, mongongo nuts, manketti nuts, or nongongo. The egg-shaped, velvety fruit ripens and falls between March and May each year and contains a thin layer of edible flesh around a thick, hard, pitted shell. Inside this shell is a highly nutritious nut.
 

Nuts

A nut is a fruit composed of a hard shell and a seed, which is generally edible.

There is an additional requirement in botany that the shell does not open to release the seed (indehiscent). In a general context, a wide variety of dried seeds are called nuts, but in a botanical context, only ones that include the indehiscent fruit are considered true nuts.