Maize (Zea mays)

Zea mays, commonly called maize or corn, is a tall, stout cereal grass with a single stem bearing pollen-producing tassels at its top and separate female flower clusters, or ears, lower on the stalk that develop into the kernel-bearing cob. It was domesticated by indigenous peoples in what is now southern Mexico roughly nine thousand years ago from the wild grass teosinte, likely in the Balsas River valley, with milling tools bearing maize residue found in an eight thousand seven hundred year old cave layer near Iguala, Guerrero. Unlike its wild ancestor, domesticated maize kernels no longer fall freely from the cob, leaving the plant dependent on humans for propagation, and Native American farmers commonly grew it together with beans and squash in the Three Sisters polyculture. Following its spread beyond the Americas after 1492, maize became the most produced grain in the world by weight, exceeding wheat and rice combined, with global production reaching about one point one six billion tonnes in 2020.