The Story of Cotton
No one knows who were the first people to wear clothes made from cotton or where they lived. Archaeologists have found traces of cotton fabrics dated at about 2300 b.c.e. in the ruins of Mohenjo-Daro. At that time the two cities of Mohenjo-Daro and Harappa, in the Indus Valley along what is now the border between Pakistan and India, were just emerging as the centers of a civilization that lasted until about 1700 b.c.e., when the climate became drier, crops failed, and the cities and other settlements were abandoned. People were also wearing cotton garments between 3500 and 2300 b.c.e. in the Tehuacan Valley of Mexico. The Mexican textiles were made from fully domesticated cotton (Gossypium hirsutum), suggesting an earlier history of domestication that may have taken place in South America, but based there on a different species, G. barbadense. It was being used in 3600 b.c.e. in the northern part of the Atacama Desert in Chile, and in 2500 b.c.e. along the coasts of Ecuador and Peru. At that time the cotton was still at an early stage in its domestication. Mexican cotton (G. hirsutum) still grows wild along the coasts of Central America and southern North America, but wild South American cotton (G. barbardense) is now found only along the coast of Ecuador.
The cotton plant is either a low-growing herb, a shrub about two feet (60 cm) tall, or a small tree up to six feet (1.8 m) tall. It may be an annual, biennial, or perennial—a biennial plant is one that completes its life cycle in two years. Modern cotton growers treat the plant as an annual, planting it anew each year. That is a consequence of domestication, because growers repeatedly selected annual plants.
Cotton is useful because it yields several products. Its seeds develop inside a covering of hairs that are 3,000 times longer than they are wide, mixed with much shorter hairs called fuzz. The long hairs are spun into threads, and one pound of raw cotton contains about 90 million individual fibers (200 million per kilogram). The fuzz is made into felt, cotton wool, and other products. Cottonseeds are pressed for their oil, the seeds can also be made into a high-protein flour, and seedcake made from pressed cottonseeds is a nutritious cattle feed. Cotton is unusual among crop plants in that it was domesticated independently twice in Central and South America, once in Africa, and once in Asia. There are 39 species of Gossypium that grow naturally in warm-temperate and tropical regions. Of these, four species have been domesticated.
African or West Asian cotton (G. herbaceum) is a perennial shrub found in savanna and semidesert environments in Arabia and in Africa south of the Sahara. It was domesticated in either Ethiopia or southern Arabia, and knowledge of its cultivation spread eastward into Persia (Iran), Afghanistan, Turkestan, and China, where it was being grown in about 600 c.e., and northward into Turkey, Ukraine, and southern Europe.
Asian cotton (G. arboreum) is the species that was domesticated in the Indus Valley. Some varieties of Asian cotton are annual plants and others are perennial shrubs. One of the perennial varieties was introduced to East Africa, and about 2,000 years ago the Meroe people of Nubia were growing it. In ancient times Nubia was a region to the south of Egypt, extending westward to the edge of the Libyan Desert, southward about to Khartoum, and eastward to the Red Sea. The cultivation of Asian cotton spread westward from Nubia, eventually reaching Nigeria. In the ninth century the city of Kano, Nigeria, was a center for cotton textile production.
South American cotton (G. barbadense) was fully domesticated by 1000 b.c.e., and its cultivation spread throughout much of South America and eastward to the Caribbean islands. Christopher Columbus encountered it in Barbados, which is how it acquired the specific name barbadense. This was the species that came to be grown on the slave plantations of the British West Indies. By the 1650s Barbados was exporting cotton, and in about 1670 cotton planters brought the crop from Barbados to the British North American colonies, founding the North American cotton industry.
Mexican cotton (G. hirsutum) was being grown extensively in many parts of Central America by the time the first Spanish explorers arrived in the early 16th century. The Maya and Aztec civilizations made great use of it, and by the first century c.e. Mexican cotton was also being grown in Arizona. Spanish colonists sent Mexican cotton to Europe, and in time its superior qualities allowed it to displace the other cultivated species. Most commercial cotton is now G. hirsutum.
- The Story of Corn
- The Story of Rice
- The Story of Wheat
- The Origins of Agriculture
- Carl Skottsberg and the Plants of Southern South America
- August Grisebach and Floral Provinces
- Edward Forbes and the Significance of Ice Ages
- Alphonse de Candolle and Why Plants Grow Where They Do
- Franz Meyen and Vegetation Regions