It has been derived from hybridization between a small domesticated maize (a slightly changed form of a wild maize) and a teosinte of section Luxuriantes (Zea), either Z. luxurians or Z. diploperennis.

Genetic studies, published in 2004 by John Doebley, identified Zea mays ssp. parviglumis, native to the Balsas River valley in Mexico's southwestern highlands, and also known as Balsas teosinte, as being the crop wild relative that is genetically most similar to modern maize. [112] [111] This was confirmed by further studies, which refined this hypothesis somewhat. Archaeobotanical studies, published in 2009, point to the middle part of the Balsas River valley as the likely location of early domestication; this river is not very long, so these locations are not very distant. Stone milling tools with maize residue have been found in an 8,700 year old layer of deposits in a cave not far from Iguala, Guerrero. [113] [114] [115] Stucco head of the Maya Maize God, 550–850 ADCorn for Home Heat: A Green Idea That Never Quite Popped". March 2, 2015. Archived from the original on March 3, 2015 . Retrieved July 7, 2017. a b Torrejón, Fernando; Bizama, Fernando; Araneda, Alberto; Aguayo, Mauricio; Bertrand, Sébastien; Urrutia, Roberto (2013). "Descifrando la historia ambiental de los archipiélagos de Aysén, Chile: El influjo colonial y la explotación económica-mercantil republicana (siglos XVI-XIX)"[Deciphering the environmental history of the Aysén archipelagos, Chile: Colonial influence and commercial exploitation during the Republican Era (XVI-XIX centuries)]. Magallania (in Spanish). 41 (1): 29–52. doi: 10.4067/S0718-22442013000100002. Feschotte, C.; Pritham, E. (2009). "A cornucopia of Helitrons shapes the maize genome". Proceedings of the National Academy of Sciences. 106 (47): 19747–19748. Bibcode: 2009PNAS..10619747F. doi: 10.1073/pnas.0910273106. PMC 2785235. PMID 19926864.

An 2002 study by Matsuoka et al.. has demonstrated that, rather than the multiple independent domestications model, all maize arose from a single domestication in southern Mexico about 9,000 years ago. The study also demonstrated that the oldest surviving maize types are those of the Mexican highlands. Later, maize spread from this region over the Americas along two major paths. This is consistent with a model based on the archaeological record suggesting that maize diversified in the highlands of Mexico before spreading to the lowlands. [15] [16] Matsuoka, Yoshihiro (January 22, 2003). "Earliest Directional Evolution for Microsatellite Size in Maize" (PDF). Science . Retrieved March 3, 2014. The breakdown of usage of the 12.1-billion- bushel (307-million-tonne) 2008 US maize crop was as follows, according to the World Agricultural Supply and Demand Estimates Report by the USDA. [161] Use It is unknown what precipitated its domestication, because the edible portion of the wild variety is too small, and hard to obtain, to be eaten directly, as each kernel is enclosed in a very hard bivalve shell. [ citation needed] Chodosh, Sara (July 8, 2021). "The bizarre botany that makes corn a fruit, a grain, and also (kind of) a vegetable". Popular Science . Retrieved February 24, 2022.Brown, David (November 20, 2009). "Scientists have high hopes for corn genome". The Washington Post. Maize harvested as a grain crop can be kept in the field a relatively long time, even months, after the crop is ready to harvest; it is also harvested and stored in the husk leaves if kept dry. [125]

Van Devender, Karl (July 2011). "Grain Drying Concepts and Options" (PDF). University of Arkansas Division of Agriculture . Retrieved December 15, 2013. Head, John W. (November 25, 2016). International Law and Agroecological Husbandry: Building legal foundations for a new agriculture. Routledge. ISBN 978-1-315-44650-9. Ears develop above a few of the leaves in the midsection of the plant, between the stem and leaf sheath, elongating by around 1⁄ 8in) per day, to a length of 18cm (7in) [51] with 60cm (24in) being the maximum alleged in the subspecies. [58] They are female inflorescences, tightly enveloped by several layers of ear leaves commonly called husks.Birchler, James A.; Han, Fangpu (December 1, 2009). "Maize Centromeres: Structure, Function, Epigenetics". Annual Review of Genetics. 43 (1): 287–303. doi: 10.1146/annurev-genet-102108-134834. PMID 19689211. Himi, E; Mares, DJ; Yanagisawa, A; Noda, K (2002). "Effect of grain color gene (R) on grain dormancy and sensitivity of the embryo to abscisic acid (ABA) in wheat". Journal of Experimental Botany. 53 (374): 1569–74. doi: 10.1093/jxb/erf005. PMID 12096095.