The yam bean (Pachyrhizus erosus) belongs to Fabaceae (the Pea family). It is a perennial herb that is native to Central America. Nowadays, it is caltivated widely in the tropical areas. This herb is a vine with trifoliate leaves. The flowers are white to purple, papilionacenous and bloom in the racemes. The tuber is large, spherical or elongated, about 40 cm diameter and up to 15 kg weight. The white flesh of tuber can be eaten cooked or raw.