a genus of four wild Mexican and Mesoamerican species of large grasses of the family Poaceae, order Poales. The two best-known grasses are members of Zea mays, which has four subspecies. In particular, corn, or maize (Z. mays mays), belongs to a worldwide cultigen derived from one of the Mexican teosintes (subspecies parviglumis) in pre-Columbian times more than 5,000 years ago.