Some 4,000 years ago, native North Americans of what is now Arkansas, Missouri, Kentucky, Tennessee and surrounding states were domesticating a whole set of crops, most of which you have probably never heard of.
For reasons we do not fully comprehend, when ancient peoples made the transition to agriculture, they never domesticated just one crop by itself. In the first stage of agriculture, first farmers planted and tended wild plants, species which they and their ancestors had been gathering for generations. Within a few centuries, the farmers would select for larger seeds or roots, depending on which part of the plant they ate. This change in form is usually what archaeologists refer to as domestication. By more stringent definitions, domestication is when the plant can no longer reproduce on its own, in the wild, as is the case with maize and potatoes.
The native North Americans domesticated the sunflower (Helianthus annuus), but also the summer squashes (yellow and green varieties) and the acorn squash, all derived from Cucurbita pepo. The other ancient North American crops included the little barley (Hordeum pusillum), goosefoot or lambsquarters (Chenopodium berlandieri), erect knotweed (Phalaris caroliniana) and sumpweed or marsh elder (Iva annua).
Besides the little squashes and the radiant sunflower, the other native crops now survive only as weeds. As North America was one of the last centers of domestication, the crops may still have been robust enough, just wild enough, to reproduce themselves as weeds. As my wife Ana noticed, the sunflower itself is a hardy, fast-growing, weedy-looking plant before it starts to flower (pictured).
Except for the sunflower and the squashes, all the other North American crops were slowly abandoned, probably because they were much less productive than other crops (maize, beans and the larger squashes) which arrived from Mexico, about 100 BC. But the sunflower was valued for food (including oil), dye and even medicine.
Another 1700 years later, the settlers in North America were uninterested in growing the sunflower, although they happily adopted maize, beans and squash. The settlers certainly knew of the sunflower, but they had a diet that was fairly rich in animal fats, especially from pork, and may have found it too tedious to process the oily little sunflower seeds. But many wild species of sunflower still thrived all over the continent.
The sunflower was taken from Mexico to Spain in the 1500s and slowly spread across Europe, largely as an ornamental, eventually reaching as far east as Russia. The sunflower might have ended as an obscure garden flower, if religious taboo had not dealt it a winning hand. During lent, the Russian Orthodox Church banned butter and lard, but sunflower oil was too new to appear on the list of banned oils. The demand for sunflower oil surged, leading V. S. Pustovit of Krasnodar to breed a sunflower with a much larger seed head. Named the Russian Mammoth, this variety was introduced to the USA in 1893. The sunflower slowly gained in importance, but did not become an important crop in the USA until the 1950s
At first the crop was almost entirely exported as oil to Europe, but stiff competition from Europe and Argentina ended that market, and most US sunflower is consumed domestically.
Modern plant breeding saved the sunflower. By 2010 there were 750,000 hectares of sunflower planted in the USA, worth $634 million at the farm gate. About 60% of the crop is used as oil and meal, and 10 to 20% is for snack food and baking. About a quarter of the sunflower harvest is made into birdseed: in 2006 the USA spent $3.35 billion feeding wild birds, roughly equal to the GDP of Fiji.
Under the changing pressure of economic demand, a crop can evolve quickly, from garden flower to Lenten oil to bird food. Once abandoned as a crop in its center of origin, the sunflower is now here to stay, thanks to a little love from Russia and plant breeders.
Selig, Ruth Osterweis 2004 Origins of agriculture in Eastern North America, pp. 258-272. In Ruth Osterweis Selig, Marilyn R. London and P. Ann Kaupp Anthropology Explored (Second Edition). Washington: Smithsonian Books. 473 pp.
Smith, Bruce D. 2014 The domestication of Helianthus annuus L. (sunflower). Vegetation History and Archaeology 23(1):57-74
USDA 2015 Sunflower seed. http://www.ers.usda.gov/topics/crops/soybeans-oil-crops/sunflowerseed.aspx