Common cultivated wheat originates from Asia in the region between the Tigris and Euphrates rivers. This area has numerous species of wild grass which are closely related to wheat. From the Middle East, wheat cultivation spread in all directions.
The earliest forms of wheat, harvested by man over twelve thousand years ago, were Triticum monococcum and T. dicocccum, notable for fragile ears which shatter and disperse when mature.
Wheat belongs to the grass family (Poaceae), with Triticum durum and T. compactum being the most cultivated varieties. Hexaploid wheat, T. aestivum, is the most cultivated cereal for breadmaking in the world.