Rye (grain)

Rye (grain), common name for an annual cereal grain, of the grass family, allied to wheat and barley (see Cereals; Grasses). Rye is native to temperate Eurasia where it is most heavily used as a bread grain (mixed with other grains) and as a livestock feed. It is less important as a grain crop in other parts of the world. Rye is also used as hay and straw; its straw, tougher than that of other cereals, is valued for straw plait. In addition, mashes of more than 50 percent rye are used to make rye whiskey (see Whiskey).

The rye plant is characterized by slender seed spikes that consist of two or more flowered spikelets. The florets, which have rows of barbs and long terminal beards, or awns, must be cross-pollinated by the wind, unlike the florets of wheat and other grains. Several varieties of rye have been developed. All are hardier in winter than other cereals; the most extensively cultivated varieties, specifically called winter ryes, are adapted for sowing in autumn, whereas others are sown in the spring.

Rye was first cultivated rather late in human history, perhaps as recently as 2000 to 3000 years ago. It is still grown extensively in northern Europe and Asia. It lacks the proteins that make wheat suitable for leavening, and rye bread is denser and usually darker than wheat bread. Rye infested with a fungus called ergot was responsible for several epidemics in medieval times.

Two other species exist in the same genus as the rye plant. A distantly related genus contains species known as wild ryes that are used as cover and for forage; a wheat hybrid is known as giant rye.

Scientific classification: Rye belongs to the family Poaceae (formerly Gramineae). It is classified as Secale cereale. Wild ryes are classified in the genus Elymus. The giant rye is classified as Elymus condensafus.