Didn't Britain back in the early 50's sponsor a big scheme growing groundnuts to help the African colonies and in effect were they not peanuts?
Good old Wiki...
Peanut, also known as
groundnut and
goober (
Arachis hypogaea), is a crop of global importance. It is widely grown in the
tropics and subtropics, being important to both smallholder and large commercial producers. It is classified as both a grain
legume, and, because of its high oil content, an oil crop. World annual production is about 46 million
tonnes per year. Peanut pods develop under the ground, which is very unusual among crop plants.

Peanuts
As a legume, peanut belongs to the botanical
family Fabaceae (also known as
Leguminosae, and commonly known as the bean or pea family). Like most other legumes, peanuts harbor
symbiotic nitrogen-fixing bacteria in
root nodules. This capacity to fix nitrogen means peanuts require less nitrogen-containing
fertilizer and improve
soil fertility, making them valuable in
crop rotations.
Peanuts are similar in taste and nutritional profile to tree nuts such as
walnuts and
almonds, and are often served in similar ways in Western cuisines. The botanical definition of a "
nut" is a
fruit whose ovary wall becomes very hard at maturity. Using this criterion, the peanut is not a nut, but rather a legume. However, for culinary purposes and in common English language usage, peanuts are usually referred to as nuts.