Maize
From Wikipedia, the free encyclopedia
This article is about the cereal grain. For other uses, see Maize (disambiguation).
"Corn" redirects here. In British English, "corn" can mean any cereal. For other uses, see Corn (disambiguation).
| Maize | |
|---|---|
 | |
| Illustration depicting both male and female flowers of maize | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Monocots |
| (unranked): | Commelinids |
| Order: | Poales |
| Family: | Poaceae |
| Subfamily: | Panicoideae |
| Tribe: | Andropogoneae |
| Genus: | Zea |
| Species: | Z. mays |
| Subspecies: | Z. mays subsp. mays |
| Trinomial name | |
| Zea mays subsp. mays L. | |
Maize (/ˈmeɪz/ mayz; Zea mays subsp. mays, from Spanish: maíz after Taíno mahiz), known in some English-speaking countries as corn, is a largegrain plant domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain the grain, which are seeds called kernels. Maize kernels are often used in cooking as a starch.
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[show]History
Most historians believe corn was domesticated in the Tehuacan Valley of Mexico.[1] The Olmec and Mayans cultivated it in numerous varieties throughout Mesoamerica, cooked, ground or processed through nixtamalization. Beginning about 2500 BC, the crop spread through much of theAmericas.[2] The region developed a trade network based on surplus and varieties of maize crops. After European contact with the Americas in the late 15th and early 16th centuries, explorers and traders carried maize back to Europe and introduced it to other countries. Maize spread to the rest of the world because of its ability to grow in diverse climates. Sugar-rich varieties called sweet corn are usually grown for human consumption, while field cornvarieties are used for animal feed and as chemical feedstocks.
Maize is the most widely grown grain crop throughout the Americas,[3] with 332 million metric tons grown annually in the United States alone. Approximately 40% of the crop — 130 million tons — is used for corn ethanol.[4] Genetically modified maize made up 85% of the maize planted in the United States in 2009.[5]
Words for maize
The word maize derives from the Spanish form of the indigenous Taíno word for the plant, maiz.[6] It is known by other names around the world.
Corn outside North America, Australia, and New Zealand means any cereal crop, its meaning understood to vary geographically to refer to the localstaple.[7][8] In the United States,[7] Canada,[9] Australia, and New Zealand,[citation needed] corn primarily means maize; this usage started as a shortening of "Indian corn".[7] "Indian corn" primarily means maize (the staple grain of indigenous Americans), but can refer more specifically to multicolored "flint corn" used for decoration.[10]
In places outside North America, Australia, and New Zealand, corn often refers to maize in culinary contexts. The narrower meaning is usually indicated by some additional word, as in sweet corn, corn on the cob, popcorn, corn flakes, baby corn.
Maize is preferred in formal, scientific, and international usage because it refers specifically to this one grain, unlike corn, which has a complex variety of meanings that vary by context and geographic region.[8] Maize is used by agricultural bodies and research institutes such as the FAO and CSIRO. National agricultural and industry associations often include the word maize in their name even in English-speaking countries where the local, informal word is something other than maize; for example, the Maize Association of Australia, the Indian Maize Development Association, the Kenya Maize Consortium and Maize Breeders Network, the National Maize Association of Nigeria, the Zimbabwe Seed Maize Association. However, in commodities trading, corn consistently refers to maize and not other grains.[citation needed]
Structure and physiology
The maize plant is often 2.5 m (meters) (8 ft) in height, though some natural strains can grow 12 m (40 ft).[12] The stem has the appearance of a bamboo cane and is commonly composed of 20 internodes of 18 cm (7 in) length.[13][14] A leaf grows from each node, which is generally 9 cm (3.5 in) in width and 120 cm (4 ft) in length.
Ears develop above a few of the leaves in the midsection of the plant, between the stem and leaf sheath, elongating by[citation needed] ~ 3 mm/day, to a length of 18 cm (7 in) (60 cm/24 in being the maximum observed in the subspecies[15]). They are female inflorescences, tightly enveloped by several layers of ear leaves commonly called husks. Certain varieties of maize have been bred to produce many additional developed ears. These are the source of the "baby corn" used as a vegetable in Asian cuisine.
The apex of the stem ends in the tassel, an inflorescence of male flowers. When the tassel is mature and conditions are suitably warm and dry, anthers on the tassel dehisce and release pollen. Maize pollen is anemophilous (dispersed by wind), and because of its large settling velocity, most pollen falls within a few meters of the tassel.
Elongated stigmas, called silks, emerge from the whorl of husk leaves at the end of the ear. They are often pale yellow and 7 in (178 mm) in length, like tufts of hair in appearance. At the end of each is a carpel, which may develop into a "kernel" if fertilized by a pollen grain. The pericarp of the fruit is fused with the seed coat referred to as "caryopsis", typical of the grasses, and the entire kernel is often referred to as the "seed". The cob is close to a multiple fruit in structure, except that the individual fruits (the kernels) never fuse into a single mass. The grains are about the size of peas, and adhere in regular rows around a white, pithy substance, which forms the ear (maximum size of kernel in subspecies is reputedly 2.5 cm/1 in [16]). An ear commonly holds 600 kernels. They are of various colors: blackish, bluish-gray, purple, green, red, white and yellow. When ground into flour, maize yields more flour with much less bran than wheat does. It lacks the protein gluten of wheat and, therefore, makes baked goods with poor rising capability. A genetic variant that accumulates more sugar and less starchin the ear is consumed as a vegetable and is called sweet corn. Young ears can be consumed raw, with the cob and silk, but as the plant matures (usually during the summer months), the cob becomes tougher and the silk dries to inedibility. By the end of the growing season, the kernels dry out and become difficult to chew without cooking them tender first in boiling water.
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