The sunflower (Helianthus annuus) is one of the few major food crops to originate in North America. It is also one of the more surprising: a wild plant turned into a farmed crop, carried across the Atlantic as a garden curiosity, and then reinvented as an oilseed in Russia.
A native crop
Sunflowers were domesticated in North America roughly 4,500 to 5,000 years ago, depending on which source you consult. Native peoples used the plant for food, medicine, fibre and dye, among other things. In the wild the plant branches freely and carries many small, teacup-sized heads; the form cultivated by Native Americans was single-headed, with one large flower on a single stem.
Where it began has been argued over. A 2011 study led by Benjamin Blackman, published in the Proceedings of the National Academy of Sciences, compared the genetics of wild and domesticated sunflowers and concluded that the crop was domesticated once, in eastern North America and probably in the Mississippi River Valley. Sunflowers grown in Mexico descend from that same lineage, rather than from a separate Mexican domestication as had previously been suggested.
A garden curiosity in Europe
Sunflowers reached Europe in the early 16th century. One account dates seed arriving in Spain to 1510. For roughly two centuries they were mainly ornamental plants, with some minor medicinal use. The English herbalist John Gerard grew them in his garden in Holborn, London. His plants reached about 4.3 metres, while those of his European rivals reached 7.3 metres.
How Russia made it an oil crop
The turning point was religious as much as agricultural. The Russian Orthodox Church's rules for Lent listed the oils and fats that were forbidden, and sunflower oil, being new, was not on the list. Farmers in Russia and Ukraine began growing it for oil, and by the early 1800s the area under sunflowers across the two countries had passed 800,000 hectares.
In the 20th century, the Soviet breeder Vasilii Pustovoit selected plants for oil content. Seeds held about 30% oil in 1913 and about 50% by the late 1950s, much of that gain coming from thinner hulls around the kernel. His variety Peredovik later underpinned commercial sunflower oil production in the West. In 1969 the French researcher Leclercq developed a method using male sterility that made true hybrid sunflowers possible, and in 1970 the American scientist Kinman worked out how to restore fertility in the hybrids. Today sunflower oil ranks fourth among crop oils, behind palm, soybean and canola, and Ukraine and Russia together grow more than half the world's supply.
The crop then travelled back across the Atlantic. In the 1880s, Ukrainian and Russian Mennonite farmers brought sunflower seed with them to the northern Great Plains of North America.
Oil seeds and eating seeds
Breeders developed two broad kinds. Oilseed varieties have small black achenes, the single-seeded fruits we call seeds. Confectionery varieties have larger black-and-white achenes, and the kernel separates easily from the shell. That kernel can be eaten dried or roasted, or ground into seed butter. The pressed oil is sweet and yellow, and the Encyclopaedia Britannica compares it with olive or almond oil for table use. The oil cake left after pressing is used as livestock and poultry feed.
Why sunflowers follow the sun
Young sunflowers do track the sun, but old ones do not. A 2016 study in Science by researchers at UC Davis and colleagues found that young plants face east at dawn, turn west through the day and swing back east overnight, driven by an internal circadian clock that makes the east side of the stem grow faster by day and the west side by night. Once the flower opens and growth slows, the plant stops moving and settles facing east. The researchers found that east-facing flowers warmed faster in the morning and attracted about five times as many pollinating insects.
What "sprouted and raw" means
Our seeds are soaked and rinsed with pure water until they begin to germinate, then dehydrated below 40°C. The low drying temperature is why we call them raw. The result keeps a nice crunch and a mild, nutty taste. Germination starts when a seed takes up water, which wakes the enzymes stored inside it; they begin breaking down the seed's stored food for the growing embryo.
Using them
Straight from the pouch they work as a snack, in salads or in stir-fries. They can also be blended into sunflower seed butter or pesto.
Sources
- Encyclopaedia Britannica: Sunflower
- The Conversation: Making sunlight liquid, a brief history of sunflowers
- Nuseed: History of the sunflower
- University of Arkansas Cooperative Extension: Sunflowers
- A Moment of Science: North American origin of domesticated sunflowers (Blackman et al., PNAS, 2011)
- Biologists confirm sunflower domesticated in US, not Mexico (2011)
- ScienceDaily: How sunflowers follow the sun (Atamian et al., Science, 2016)
- University of Arizona Cooperative Extension: How seeds work
