The corn plant has a pithy noded stalk supported by prop roots. The staminate (male) flowers form the tassel at the top of the plant. The pistillate (female) flowers are the kernels on the cob, which is enclosed by a leafy husk beyond which extend threadlike styles and stigmas (the silk), which catch the pollen. The corn plant with its ornamental tassel and ears has been a motif of American art since prehistoric times.

The plant is a grass that was domesticated and cultivated in the Americas long before Europeans reached the New World; genetic and archaeological evidence indicates it was first domesticated c.7000 b.c. Corn has dramatically changed from the ancestral wild grass that was its original form, teosinte (Zea species), a tropical American fodder plant in which the seeds are not united in a cob. It has been so adapted to cultivation that it cannot sustain itself without human cultivation. The Native Americans had many varieties of corn, e.g., sweet corn, popcorn, and corn for corn meal. White, yellow, red, and blue corn were grown as distinct strains.

The easily produced and readily identifiable strains of corn made it a favorite subject for experimental genetics. The development of hybrid corn seed was an early (beginning of the 20th cent.) and revolutionary introduction of the principles of theoretical science into practical agriculture. At first ridiculed, the scientifically developed hybrids came to represent most commercially grown corn types. They resulted in higher yields, increased sugar and lowered starch content, and uniform plants bred to specification for mechanical harvesting. Most recently, genetic engineering has produced corn with added sweetness, disease resistance, and other desired traits.

As human food, corn is eaten fresh or ground for meal. It is the basic starch plant of Central and Andean South America, where it is still hand ground on metates to be made into tamales, tortillas, and other staple dishes. In the S United States it is familiar as hominy, mush, and grits. Starch, sugar, and oil are also extracted for many products, but the chief use of corn is as animal fodder. It is the primary feed grain of the United States, and in Europe this is almost the only use of corn. Corn is also as a raw material in the manufacture of ethanol for fuel.