Zea mays parvaglumis or mexicana
About 9,000 years ago, humans began to interact with wild teosinte in the balsas River Valley of southern-central Mexico. Over several thousand years of seed stewardship our ancient ancestors developed domesticated corn and the thousands of different varieties that exist today.
Teosinte is not consumed widely. In Mexico the stalk is chewed for its sweet juices, reminiscent of sugar. Archaeological evidence suggests the sweet juice from the stalks of teosinte was consumed prior to the discovery of the grain. The hard outer casing of teosinte makes the dry grain inedible. It was a genetic mutation that caused this hard outer coating to disappear. Ancient plant breeders took advantage of this trait by saving and planting these kernels, essentially making corn what it is today.
Teosinte is an extremely important crop, as it believed that the subspecies parviglumis is the wild progenitor of corn. About 9,000 years ago, teosinte grew wild, as a grass-like plant, with a grain in a tough shell that was dispersed only when ripe. About 9,000-6,000 years ago, ancient people began to develop parviglumis teosinte into a crop that more closely resembles what we know as corn. Its kernels started to grow without the tough shell, and humans domesticated this plant for its grain, changing the size and textures of the kernels. This mutation causing the loss of the shell meant that the plant could no longer grow wild in its current form, since the kernels were unprotected from predators such as birds. Through these interactions with humans, it is thought that corn developed into the plant it is now.
Teosinte has never grown in the American Southwest. Domesticated corn was grown in the Southwest by 4,000 years ago. As domesticated varieties of corn were moved from central Mexico throughout the Americas it cross-pollinated other subspecies of teosinte including Zea mays mexicana which is native to Northwest Mexico.
Farmers in Mexico and Central America still let the wild teosinte plants grow around the edges of their cornfields as it is believed that the teosinte makes the corn plants ‘stronger’. This is because the genetic transfer between wild and domesticated varieties diversifies the genetic code of the domesticated corn, reducing impacts of inbreeding and genetic narrowing. The pollen from teosinte can pollinate the silks of the domesticated corn because they are still very closely related. This diversity leads to healthier populations. Teosinte is widely used as a forage crop for cattle in Mexico and the seeds may be fed to other livestock such as chickens and pigs.
Teosinte is considered the mother of corn and therefore holds a very important place in indigenous culture and beliefs. For many indigenous societies of the Americas corn is considered the mother of all people and is the most important cultivated crop. The name teosinte is derived from the Nahuatl word tosintli which means sacred corn. Many indigenous peoples visiting the Native Seeds/SEARCH seed bank facility have honored teosinte. One memorable moment came from Martina, a young Zapotec teacher from Oaxaca. She began to cry when holding the precious teosinte seeds. She spoke of how her family and culture have stories about sacred teosinte, but she had never been able to see it. To hold it was something very precious to her.
Teosinte commonly grows wild in Southern Mexico, along stream sides and on hillsides, but is also found in waste-ground and along field boundaries. Teosinte plants do not produce flowers or the tassels until the shorter days of autumn, making it difficult to harvest seed in frost-prone areas in North America. Its natural range does not extend beyond southern Chihuahua.
This wild ancestor to domesticated corn shares many of the same traits as modern corn. However, the ears are small (2-3") with only 1 row of triangular shaped seeds. Plants will produce silks and tassels, but will be bushier with many branches. Each seed is enclosed by a very hard fruit case that protects it in the wild. Soak seeds overnight to aid in germination.
Teocintle. (2015). Retrieved from http://www.biodiversidad.gob.mx/usos/maices/teocintle2012.html
Boutard, Anthony (2012) Beautiful Corn: America’s Original Grain from Seed to Plate. Vancouver, Canada: New Society Publishers.
Mondragon, J. & Vibrans, H. (2005). Ethnobotany of the Balsas Teosinte. Maydica: 50, 123-128. Retrieved from http://www.maydica.org/articles/50_123.pdf
Evolution of Corn. Retrieved from http://learn.genetics.utah.edu/content/selection/corn/
Popped Secret: The Mysterious Origin of Corn. Retreived from http://www.hhmi.org/biointeractive/popped-secret-mysterious-origin-corn