Oats probably slipped into farming by looking like other cereals
Early cultivators seem to have gathered oat seeds along with other cereals because they looked so alike, and the hitchhiker became a crop in its own right. Oats dislike harsh winters but thrive in cool, rainy summers, which is why they flourished in places like northwest Europe.
The common oat, Avena sativa, is a cereal grass grown for grain and animal fodder. Compared with wheat, barley and rye it copes worse with cold winters but needs less summer heat and more rain. It also tolerates poor, acidic soils, grows densely enough to smother many weeds and suffers relatively few diseases. Canada and Russia dominate world production, and most of the harvest is eaten in the country that grows it, with only a small share traded internationally.
The plant can reach 1.8 metres, with long, narrow leaves up to 40 centimetres. Its fibrous roots mostly stay in the top 30 centimetres of soil, though some reach 1.5 metres. Crowded seedlings send up only one or two hollow stems, while well-spaced plants may produce 10 to 30. At the top, each stem opens into a loose panicle of 10 to 75 spikelets carrying wind-pollinated flowers that mostly fertilise themselves, with only 1 to 2 percent crossing. Each grain is a caryopsis, a fruit whose wall is fused to the seed, containing bran, a starchy endosperm and a protein-rich germ.
Oat genetics are unusually complex. Avena sativa is hexaploid, carrying six sets of chromosomes, and descends from the wild oat A. sterilis, whose ancestors grew in the Fertile Crescent. Studies of chloroplast and mitochondrial DNA from 25 species trace its genome to several diploid and tetraploid oats; four-set forms arose as much as 10.6 million years ago and six-set forms perhaps 7.4 million years ago. Within the grass family, oats sit in the same subfamily as wheat, barley and rye but in a different tribe.
People eat oats as oatmeal, whether steel-cut or rolled, and regular consumption has been associated with lower blood cholesterol and reduced risk of heart disease. Much of the crop feeds livestock, and farmers also sow oats as ground cover to plough back in as green manure.
Source: Oat
