A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize (corn). Edible grains from other plant families, such as amaranth, buckwheat and quinoa, are pseudocereals. Most cereals are annuals, producing one crop from each planting, though rice is sometimes grown as a perennial. Winter varieties are hardy enough to be planted in the autumn, becoming dormant in the winter, and harvested in spring or early summer; spring varieties are planted in spring and harvested in late summer. The term cereal is derived from the name of the Roman goddess of grain crops and fertility, Ceres.
Cereals were domesticated in the Neolithic around 8,000 years ago. Wheat and barley were domesticated in the Fertile Crescent. Rice and some millets were domesticated in East Asia, while sorghum and other millets were domesticated in West Africa. Maize was domesticated by Indigenous peoples of the Americas in southern Mexico about 9,000 years ago. In the 20th century, cereal productivity was greatly increased by the Green Revolution. This increase in production has accompanied a growing international trade, with some countries producing large portions of the cereal supply for other countries.
