Macadamia nut (Macadamia tetraphylla) has a rough shell, and is the subject of some commercialization [REF].
Peanut, or groundnut (Arachis hypogaea), originally from South America, has grown from a relatively minor crop to one of the most important commercial nut crops, in part due to the work of George Washington Carver at the beginning of the 20th century [REF].