From The Food Encyclopedia by Jacques Rolland and Carol Sherman
A kidney-shaped legume, Phaseolus vulgaris, in a variety of colors, ranging from white to light red to dark red, usually dried. Grows in an elongated, straight or slightly curved pod. Originating in Peru, the bean spread throughout South and Central America by migrating Indian traders. The English first used the name "kidney bean" in 1551 to distinguish this New World bean from Old World types. Kidney beans that are white in color are known as cannellini beans.
