Description:

The peanut,or groundnut (Arachis hypogaea), is a species inthe legume or "bean" family (Fabaceae). Thepeanut was probably first domesticated and cultivated in thevalleys of Paraguay. It isan annual herbaceous plant growing 30 to 50 cm (1.0to 1.6 ft) tall. Theleaves are opposite, pinnate with four leaflets (two opposite pairs; noterminal leaflet), each leaflet 1 to 7 cm (0.36 to 2.75 in)long and 1 to 3 cm (0.36 to 1 inch) broad.

The flowers are a typicalpeaflower in shape, 2 to 4 cm (0.8 to 1.6 in) (0.75 to 1.5 in)across, yellow with reddish veining. Hypogaea means"under the earth"; after pollination, the flower stalkelongates causing it to bend until the ovary touches the ground.Continued stalk growth then pushes the ovary underground where themature fruit develops into a legume pod, thepeanut – a classical example of geocarpy. Pods are 3 to 7cm (1.2 to 2.8 in) long, containing 1 to 4 seeds.

Peanuts are known bymany other local names such as earthnuts,  ground nuts, goober peas,  monkey nuts,  pygmynuts and pig nuts. Despite its name and appearance,the peanut is not a nut, but rather a legume.