Barley Hordeum distichum or Hordeum vulgare is a type of grass like wheat and rice. It has been cultivated in the Middle East for thousands of years and is now one of the most prominent seed crops grown in the world. Twenty species are known, of which eight are European. Barley needs less rain than wheat does, so in the Holy Land it was typically found in the drier areas above the coastal plain and near the desert. From 2 Kings 7:1 and Revelation 6:6 we know that barley was considered inferior to wheat and was often used to feed animals, as it is today. When the wheat supply ran out, people had to make their bread with barley. Barley was gathered before wheat, the harvest coming around March or April in the lower regions and in May in the mountains (see Exodus 9:31 et al.). In Egypt and in ancient Greece barley was used to make beer.
Barley plants look like wheat or rice. They are less than 1 meter (3 feet) tall, and have a single head on each stalk, with six rows of kernels, although the biblical kind may have had only two rows. The head bends at a down-ward angle when it is ripe.
In the story of Gideon and the Midianites in Judges 7:13, “a cake of barley” representing the (despised) Israelite army tumbles into the Midianite camp and knocks down the tent (representing the nomadic Midianites).
Barley is a plant of temperate zones, like Europe and the Near East; it does not grow well in the tropics. However, barley has been recently introduced along with wheat into many parts of the world for brewing beer and other malted drinks. It is also known to have grown in Korea as early as 1500 B.C. along with wheat and millet. It is becoming known in Malay as barli. Except for the reference in Judges, all references to barley in the Bible are non-rhetorical, so unrelated cultural equivalents are discouraged. Some receptor language speakers may coin a name for it as in Malay, or the translator can use a transliteration from Hebrew (se‘orah), Latin (horideyo), or from a major language (for example, Arabic sha’ir, Spanish cebada, French orge, Portuguese cevada, Swahili shayiri), together with a classifier, if there is one (for example, “grain of shayir”).
Source: Each According to its Kind: Plants and Trees in the Bible (UBS Helps for Translators)
See also barley bread.