1. Family: Poaceae Barnhart
    1. Genus: Secale L.
      1. Secale cereale L.

        Rye (Secale cereale) is an extremely hardy crop and can survive harsh conditions and difficult soils where wheat and barley struggle to grow. Rye is commonly grown in the fields of Northern and Eastern Europe where it can produce a good harvest despite the cold winters and hot dry summers of the region. Rye is considered to be a ‘secondary crop’ meaning that it first appeared as a weed growing alongside wheat and barley in farmers fields and then was domesticated to become a useful grain.

    Annual; caespitose. Culms 60-150 cm long; 6-7 -noded. Leaf-sheaths glabrous on surface, or hirsute. Leaf-sheath oral hairs lacking. Leaf-sheath auricles falcate. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades 10-20 cm long; 6-10 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy.
    Inflorescence composed of racemes. Peduncle pubescent above. Racemes 1; single; bilateral; 5-15 cm long. Rhachis tough; pubescent on surface; ciliate on margins. Spikelet packing broadside to rhachis. Rhachis internodes oblong; 2-3 mm long. Spikelets solitary. Fertile spikelets sessile.
    Spikelets comprising 2 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 12-15 mm long; persistent on plant.
    Spikelets comprising 2 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 12-15 mm long; persistent on plant.
    Glumes similar; shorter than spikelet. Lower glume linear; 10-12 mm long; 1 length of upper glume; coriaceous; 1-keeled; keeled all along; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume surface puberulous. Lower glume apex acuminate; mucronate. Lower glume awn 1-3 mm long. Upper glume linear; 10-12 mm long; 0.6-0.7 length of adjacent fertile lemma; coriaceous; 1-keeled; keeled all along; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acuminate; mucronate. Upper glume awn 1-3 mm long.
    Fertile lemma lanceolate; 14-15(-18) mm long; coriaceous; keeled; 5 -veined. Lemma midvein pectinately ciliate. Lemma margins ciliate; hairy above. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 20-50 mm long overall; limb scabrous. Palea 0.6-0.7 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.
    Lodicules 2; ciliate. Anthers 3; 7 mm long. Ovary with a fleshy appendage below style insertion; pubescent on apex.
    Caryopsis with adherent pericarp; obovoid; sulcate on hilar side; 8-10 mm long. Embryo 0.33 length of caryopsis. Hilum linear.
    Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, and east tropical. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, Arabia, China, Mongolia, and eastern Asia. Asia-tropical: India and Malesia. Australasia: Australia and New Zealand. North America: Subarctic, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, and Mexico. South America: western South America, Brazil, and southern South America.
    Triticeae. Fl Iraq.

    Kew Species Profiles

    General Description

    Rye (Secale cereale) is an extremely hardy crop and can survive harsh conditions and difficult soils where wheat and barley struggle to grow. Rye is commonly grown in the fields of Northern and Eastern Europe where it can produce a good harvest despite the cold winters and hot dry summers of the region. Rye is considered to be a ‘secondary crop’ meaning that it first appeared as a weed growing alongside wheat and barley in farmers fields and then was domesticated to become a useful grain.

    Today the majority of rye is cultivated to make rye bread, also known as pumpernickel, and the rest is used in alcohol production and animal feed. In Turkey, rye is often intercropped with wheat which, in addition to serving as insurance in case the wheat harvest fails, means the two crops can be harvested together to produce a wholesome, tasty flour.

    Species Profile
    Geography and distribution

    Rye is cultivated in Europe, Africa, temperate Asia, tropical Asia (India and Malesia), Australasia, North America, Central and South America. Rye is especially common in temperate regions, although in the tropics and subtropics some farmers grow rye at high altitudes, for example, in the highlands of East Africa.

    Ethiopian rye is successfully grown by some small-scale farmers on the highlands of Arsi although there has been limited success in growing rye in Zambia and Mozambique.


    Overview:  Secale cereale  is an annual with stems up to 150 cm long and clumped together at the base.

    Leaves: Leaf blades are 10-20 cm long and 5-10 mm wide, sometimes hairless and sometimes covered in short, thin hairs.

    Flowers: The inflorescence is composed of racemes (unbranched axes along which the spikelets are arranged) 5-15 mm long. Spikelets (clustered units of flowers and bracts, typical of grasses) are 12-15mm long and comprise two fertile florets. In  Secale cereale the spikelets are solitary, fertile and attached directly to the inflorescence axis. The upper and lower glumes (empty bracts that enclose the florets) are similar in shape and size, both about 12 mm long and papery in texture.

    The apical, sterile florets resemble the fertile florets although they are underdeveloped. The flower contains two lodicules (small structures at the base of the stamens). Each flower has three anthers, is 7 mm long and the ovary is a fleshy appendage below the style. 

    Fruits: The fruit is a caryopsis (a dry fruit where the fruit wall is attached to the seed) 8-10 mm long.


    Most rye production goes into traditional European rye breads with the remainder going into animal feed and alcohol production.

    Pumpernickel bread is a dark, heavy, slightly sweet bread made from coarsely ground rye. Other rye breads are made of varying percentages of rye and wheat flour - the higher the proportion of rye, the darker the loaf. The brand Ryvita is a popular crisp flatbread made from rye that is commonly found in supermarkets in the UK. Rye flour mixed in with maize flour makes a delicious porridge eaten in some parts of Africa and, when finely milled, it can be used to make cake.

    Rye grain can be sprouted to make malt for beer. Malt made from rye can be used in a number of alcoholic beverages such as rye whisky in North America and vodka in Poland and Russia.

    Another important use of rye is as fodder, particularly in pig husbandry.

    Rye straw has a variety of applications, including as feed for cattle, thatching, mulching material, papermaking, packing material and fuel. The starch from the rye grain is used industrially in the production of glue, matches and plastics.

    In India and Europe rye is sometimes grown as a host plant for ergot (Claviceps purpurea), which is used medicinally as a treatment against migraine. Rye pollen extracts are also used as a medicine against benign prostatic hyperplasia and are commercially available in Western Europe, Japan, Korea and Argentina.

    Currently rye is being investigated as a potential biomass energy crop.

    Crop wild relatives of rye

    Wild relatives of rye are an important source of genetic diversity for the improvement of rye and other closely-related cereals such as wheat. The crop wild relative  Secale montanum , for example, is tolerant of low temperatures and high levels of soil aluminium and manganese and thus has potential as a gene source to improve other cereals. Current breeding efforts in rye agriculture are seeking to achieve yield improvement, increased protein content, cold tolerance and resistance to rust and ergot.

    The Millennium Seed Bank and the Global Crop Diversity Trust are engaged in a ten-year project, called 'Adapting Agriculture to Climate Change'. The project aims to protect, collect and prepare the wild relatives of 29 key food crops, including rye, so that they are available to pre-breeders for the development of new varieties that are more resilient to the effects of climate change.

    Millennium Seed Bank: Seed storage

    The  Millennium Seed Bank Partnership aims to save plants worldwide, focusing on those plants which are under threat and those which are of most use in the future. Once seeds have been collected they are dried, packaged and stored at -20°C in Kew’s Millennium Seed Bank vault.

    Description of seeds:  Average weight of 1,000 seeds = 20.9 g

    Number of seed collections stored in the Millennium Seed Bank:  One

    Seed storage behaviour:  Orthodox (the seeds of this plant can be dried to a low moisture content without significantly reducing their viability which means they are suitable for long-term frozen storage)

    Germination testing:  Successful

    This species at Kew

    The Economic Botany Collection houses a number of artefacts made with rye, among them this brush which has bristles woven out of rye grass. It is used in Germany and other parts of Europe to wash and brush out ovens. 

    Australia, India, Malaysia, USA
    Rye grows best in temperate climates. It can survive cold winters and hot summers and can produce a decent yield in difficult soils.
    Widespread in cultivation.
    Food, malting, fodder, fuel, glue making, thatching, mulching, papermaking.



    Found In:


    Introduced Into:

    Afghanistan, Alabama, Alaska, Alberta, Algeria, Amur, Arizona, Arkansas, Baltic States, Bangladesh, Belarus, Belgium, Brazil South, British Columbia, California, Canary Is., Central European Rus, China North-Central, China South-Central, China Southeast, Colombia, Colorado, Connecticut, Costa Rica, Cyprus, Czechoslovakia, District of Columbia, East European Russia, East Himalaya, Ecuador, Florida, France, Georgia, Greenland, Gulf of Guinea Is., Idaho, Illinois, Indiana, Inner Mongolia, Iowa, Iran, Iraq, Japan, Jawa, Kamchatka, Kansas, Kazakhstan, Kentucky, Khabarovsk, Kirgizstan, Korea, Krym, Lebanon-Syria, Libya, Louisiana, Maine, Manchuria, Manitoba, Maryland, Masachusettes, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Southwest, Michigan, Minnesota, Mississippi, Missouri, Mongolia, Montana, Morocco, Nebraska, Nevada, New Brunswick, New Hampshire, New Jersey, New Mexico, New South Wales, New York, New Zealand North, New Zealand South, Newfoundland, North Carolina, North Caucasus, North Dakota, North European Russi, Northwest European R, Northwest Territorie, Nova Scotia, Ohio, Ontario, Oregon, Pakistan, Palestine, Pennsylvania, Primorye, Prince Edward I., Québec, Rhode I., Saskatchewan, Saudi Arabia, South Australia, South Carolina, South Dakota, South European Russi, Tadzhikistan, Taiwan, Tasmania, Tennessee, Texas, Transcaucasus, Turkey-in-Europe, Turkmenistan, Ukraine, Utah, Uzbekistan, Vermont, Victoria, Virginia, Washington, West Himalaya, Western Australia, Wisconsin, Wyoming, Xinjiang, Yukon

    Common Names


    Secale cereale L. appears in other Kew resources:

    Date Identified Reference Herbarium Specimen Type Status
    Jan 1, 1968 Furse, P. [8158], Afghanistan K000782852
    Jan 1, 1960 Davis [24716], Turkey K000782843
    Jan 1, 1960 Davis [D31522], Turkey K000782844
    Price, W.R. [163], Turkey K000782842
    Rawi, A. [9184], Iraq K000782846
    Cowan [1568], Iran K000782847
    Cowan [1567], Iran K000782848
    Aellen, P. [1910], Iran K000782851

    First published in Sp. Pl.: 84 (1753)

    Accepted in:

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    GrassBase - The Online World Grass Flora
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