Barley is one of the world's major cultivated crops. It is a member of the grass family (Poaceae). In 1999, approximately142 million acres (57.5 million ha) of barley were grown worldwide and the total production was 147.0 million tons of grain (133.6 million tonnes).
The most widely cultivated species is six-rowed barley (Hordeum vulgare; also known as Hordeum sativum), which has its seeds arranged in six vertical rows on the flowering axis. The natural range of the wild barley from which the cultivated species is derived is not known for certain. Most likely, it was in southwestern Asia or northeastern Africa, now Ethiopia. The modern six-rowed barley probably has a polyphyletic origin, meaning several species in the genus Hordeum contributed genes to its evolution and domestication. The primary progenitor, however, is thought to have been a wild barley known as Hordeum spontaneum, a grass with only two rows of seeds on its flowering axis. Other contributing barleys may include Hordeum distichon and Hordeum deficiens.
There is archaeological evidence suggesting barley was gathered as a wild food 17,000 years ago. Barley has been cultivated in the Middle East for more than 8,000 years, and was domesticated at least 2,000 years before that. Within the last 5,000 years, barley has been widely cultivated throughout Eurasia. Some of the major advantages of barley as a crop are that it can be cultivated in a relatively cool, dry climate, in infertile soil, and can mature in as few as 60-80 days after planting. In fact, sixrowed barley is routinely grown further north than any other grain crop derived from a grass, such as the family Poaceae. Most barley is sown in the springtime and used primarily as livestock fodder or in the production of malt for brewing beer. In the past, barley was primarily used to make cakes and bread, as a gruel, or as a thickening ingredient in soup. These are now minor uses of the world production of barley.
There are also numerous non-crop plants in the same genus as the economically important barley species. One of these is the foxtail barley, Hordeum jubatum, a weedy plant native to marine shores having very long, attractive awns attached to its seeds.