Grain crops of the world include the food grains, the coarse or feed grains, and a few minor coarse grains. The food grains include rice (Oryza sativa) and wheat (Triticum aestivum); the coarse or feed grains are barley (Hordeum vulgare), maize (Zea mays), rye (Secale cereale), oats (Avena sativa), millets (Pennisetum and Setaria species), sorghum (Sorghum vulgare), buckwheat (Fagopyrum esculentum), and triticale X (Triticosecale wittmack). Except for buckwheat, virtually all of the grain crops are members of the grass family. The principal harvestable commodity of these crops is the grain. Grazing or hay production is a minor use of a few crops.

All of the grain crops now are distributed worldwide, although each crop generally originated in a specific region: rice in Asia; wheat, barley, oats, and rye in the Fertile Crescent of the Mideast; maize in Central America; sorghum and the Pennisetum millets in Africa. Triticale is...