Soybeans belong to the legume family and are native to East Asia. They have been an important protein source in the Orient for over five thousand years. Soybeans have only been introduced to the Western world since the 20th century. Soybeans grow on a variety of soils and a wide range of climates, ranging form tropical Brazil to the snowy island Hokkaido in the north of Japan. As soybeans mature in the pod, they ripen into hard, dry beans. Although most soybeans are yellow,there are also rare varieties which are black, brown or green coloured. A given area of land planted with soybeans can produce much more protein than land planted with other crops, or if the land were used to raise cattle.