Genus:
Hordeum L.

Hordeum marinum Huds.

A member of the grass family (Poaceae), Hordeum marinum is a salt-tolerant wild relative of the economically important cereal barley (H. vulgare).

[KSP]

Kew Species Profiles

General Description

A member of the grass family (Poaceae), Hordeum marinum is a salt-tolerant wild relative of the economically important cereal barley (H. vulgare).

Sea barley occurs on bare soil on the coast, around dried-up salty pools in salt marshes, and on rare occasions may be found on sandy or stony areas. Its tolerance of high salt levels and the water-logging that commonly accompanies it, makes sea barley a candidate for hybridisation with wheat (Triticum species). Increasing salinity of arable land is a costly problem for farmers worldwide, reducing plant growth and thus crop yields.

Species Profile
Geography and distribution

The UK is at the northern edge of the distribution of Hordeum marinum , where it grows from the south coast of Wales to its northernmost limit at the Wash. It is absent from Ireland and no longer occurs in Scotland. It is also found across the Mediterranean and parts of Central Asia on disturbed inland areas. This species has become extensively naturalised outside its native range.

Description

Sea barley grows up to 10-40 cm tall with stiff, smooth stems growing singly or clustered loosely together. Stems grow either straight upwards or outwards, spreading from a bent base. Each stem contains 3 or 4 nodes (areas from which leaves emerge). Sheaths (the lower parts of the leaf that wrap around the stem) are smooth and rounded on their backs. The leaf blade is bluish-green and narrows to a fine point at the tip. Membrane-like ligules (outgrowths on the inner side of the junction between leaf sheath and blade) are less than 1 mm in length.

Flower heads are green or purplish, spike-shaped and bristled, 2.0-6.0 cm long and 1.5-3.0 cm wide. Spikelets (single units of the flower head composed of modified leaves and flowers) occur in groups of three, alternating on opposite sides of the flowering stem. The central spikelet contains a single bisexual flower and joins directly to the flowering stem. Lateral spikelets are sterile and borne on short stalks. On fruiting, spikelets fall from the flowering stem in groups of three. Flowering and fruiting occurs during the summer

Subspecies of sea barley

There are two subspecies of sea barley. Hordeum marinum subspecies marinum is distinguished by the wide, wing-like base of the inner glumes (modified leaves at the base of spikelets) of its lateral spikelets. In contrast, H. marinum subspecies gussoneanum has a narrower inner glume that is not winged and a more variable chromosome number. Although H. marinum subspecies gussoneanum is not native to the British Isles, it is widely invasive in Britain and has been present in Guernsey for more than a hundred years. Seeds of H. marinum may colonise outside of their native range, carried as contaminants in imports of agricultural plants.

Reproduction of sea barley

Sea barley is an annual that self-pollinates and reproduces solely by seed. It requires an open habitat, performing best in mud that begins to dry during spring and is hard by the middle of the summer. Flooding in winter may help disperse the seeds, as winter flood lines from the previous year are found to contain seed deposits. Seedlings are seen in both spring and autumn; however, it is not known if either of these populations contributes more significantly to persistence of the species.

Threats and conservation

The distribution of sea barley around the south coast of England has become patchy as populations at the limits of its distribution disappear. These local extinctions are due to loss of appropriate habitat through filling-in of brackish land, land improvement, conversion of marshland grazing sites and construction of sea defences. These habitat losses have led to sea barley being listed as Vulnerable in the Vascular Plant Red Data List for Great Britain 2005 .

Another reason for its decline is that annuals such as Hordeum marinum are susceptible to competition from perennial species. Elymus pycnanthus , for example, may take over the saline habitats previously occupied by H. marinum , a problem that can be alleviated by the continuous creation of open areas, which are essential for the establishment and persistence of sea barley.

Uses

Sea barley is tolerant of high salt levels in the soil and also of the water-logging that commonly accompanies high salinity. These qualities have led to sea barley being proposed as a candidate for hybridisation with wheat ( Triticum species), with the aim of producing plants that are more suited to the increasing salinity of arable land, which can result from climate change.

Adapting Agriculture to Climate Change

Kew is one of a number of institutions collaborating on the 'Adapting Agriculture to Climate Change' project. This project seeks to combat the threat to global food security posed by climate change and will focus on collecting, protecting and preparing crop wild relatives for breeding programmes.

Hordeum marinum is an important wild relative of the major cereal grain Hordeum vulgare (barley). Previous studies of H. marinum have found that its saline tolerance makes it a possible candidate for hybridisation with wheat ( Triticum species). It is hoped that introducing traits from wild relatives to crop species will produce hybrids adapted to new climates with different demands.

Millennium Seed Bank: Saving seeds

The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Two collections of Hordeum marinum seeds are held in Kew's Millennium Seed Bank based at Wakehurst in West Sussex.

See Kew's Seed Information Database for further information on Hordeum marinum .

This species at Kew

Sea barley is not currently grown at Kew, but other Hordeum species can be seen growing here in the Grass Garden.

Pressed and dried specimens of Hordeum marinum are held in Kew's Herbarium where they are available to researchers by appointment. The details of some of these specimens, including some images, can be seen online in Kew's Herbarium Catalogue.

Distribution
United Kingdom
Ecology
Bare soil on coastlines, margins of dried-up saline pools, disturbed verges inland of sea walls and salt marshes.
Conservation
Vulnerable (VU) in Great Britain according to IUCN Red List criteria.
Hazards

Barley grasses can cause problems for sheep such as eye injuries, reduced weight gain and inferior wool quality.

[GB]
Morphology General Habit
Annual; culms solitary, or caespitose. Culms 10-40 cm long; 3-4 -noded. Leaf-sheath oral hairs lacking. Leaf-sheath auricles absent, or falcate. Ligule an eciliate membrane; 0.5-1 mm long. Leaf-blades 1.5-8 cm long; 1-3.5 mm wide.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of racemes. Racemes 1; single; oblong, or ovate; bilateral; 2-6 cm long. Rhachis fragile at the nodes; flattened. Spikelet packing broadside to rhachis. Rhachis internodes oblong; falling with spikelet above. Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels oblong.
Sterile
Companion sterile spikelets well-developed; containing empty lemmas; lanceolate; dorsally compressed; 3-5 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes markedly unequal in width; subulate; 8-26 mm long; winged on margins (upper glume); eciliate on margins. Companion sterile spikelet lemmas 1; exserted from glumes; 3-5 mm long; 1-awned; with 3-5 mm long awn.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 6-8 mm long; falling entire; deciduous with accessory branch structures. Companion sterile spikelets well-developed; containing empty lemmas; lanceolate; dorsally compressed; 3-5 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes markedly unequal in width; subulate; 8-26 mm long; winged on margins (upper glume); eciliate on margins. Companion sterile spikelet lemmas 1; exserted from glumes; 3-5 mm long; 1-awned; with 3-5 mm long awn.
Fertile
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 6-8 mm long; falling entire; deciduous with accessory branch structures.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes collateral; similar; gaping. Lower glume subulate; 10-24 mm long; 1 length of upper glume. Lower glume margins eciliate. Upper glume subulate; 10-24 mm long. Upper glume margins eciliate.
Morphology Reproductive morphology Flowers Florets
Fertile lemma ovate; 6-8 mm long; coriaceous; without keel; 5 -veined. Lemma surface smooth. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 10-24 mm long overall; limb scabrous.
Morphology Reproductive morphology Flowers
Anthers 3; 1.3-1.5 mm long. Ovary pubescent on apex.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; ellipsoid; sulcate on hilar side; hairy at apex. Embryo 0.2 length of caryopsis. Hilum linear; 1 length of caryopsis.
Distribution
Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, and south. Asia-temperate: Soviet Middle Asia, Caucasus, western Asia, Arabia, and eastern Asia. Asia-tropical: India. Australasia: Australia and New Zealand. North America: western Canada, eastern Canada, northwest USA, northeast USA, southwest USA, and Mexico. South America: southern South America.
Reference
Triticeae. CEH.

[KSP]
Use
Potential for use in crop breeding.

Native to:

Afghanistan, Albania, Algeria, Austria, Baleares, Baltic States, Belgium, Bulgaria, Canary Is., Corse, Cyprus, Czechoslovakia, East Aegean Is., Egypt, France, Germany, Great Britain, Greece, Hungary, Iran, Iraq, Italy, Kazakhstan, Kirgizstan, Kriti, Krym, Kuwait, Lebanon-Syria, Libya, Madeira, Morocco, Netherlands, North Caucasus, Pakistan, Palestine, Portugal, Romania, Sardegna, Saudi Arabia, Sicilia, Sinai, South European Russi, Spain, Tadzhikistan, Transcaucasus, Tunisia, Turkey, Turkey-in-Europe, Turkmenistan, Ukraine, Uzbekistan, West Himalaya, Yugoslavia

Extinct in:

Denmark

Introduced into:

Argentina Northeast, Argentina Northwest, Argentina South, Arizona, British Columbia, California, Cape Provinces, Chile Central, Chile South, Idaho, Illinois, Japan, Massachusetts, Mexico Northwest, Montana, Nevada, New Jersey, New South Wales, New York, New Zealand North, New Zealand South, Ohio, Oklahoma, Oregon, Pennsylvania, Queensland, South Australia, Tasmania, Utah, Victoria, Washington, Western Australia

English
Sea barley

Hordeum marinum Huds. appears in other Kew resources:

Date Reference Identified As Barcode Type Status Has image?
Burtt, B.L. [s.n.], United Kingdom K000790030 Yes
O'Byrne, J.K. [169], United Kingdom K000790032 Yes
Britton, C.E. [s.n.], United Kingdom K000790037 Yes
Hubbard, C.E. [9135], United Kingdom K000790049 Yes
Dony, J.G. [1480], United Kingdom K000790055 Yes
Johnston, H.B. [3038], United Kingdom K000790059 Yes
Wallace, E.C. [s.n.], United Kingdom K000790025 Yes
Gamble, J.S. [s.n.], United Kingdom K000790015 Yes
O'Byrne, J.K. [165], United Kingdom K000790031 Yes
Marshall, E.S. [s.n.], United Kingdom K000790006 Yes
s.coll. [s.n.], United Kingdom K000790062 Yes
Whellan, J.A. [s.n.], United Kingdom K000790038 Yes
Gamble, J.S. [s.n.], United Kingdom K000790013 Yes
Hubbard, C.E. [107], United Kingdom K000790051 Yes
Burtt, B.L. [s.n.], United Kingdom K000790029 Yes
Townsend, C.C. [s.n.], United Kingdom K000790054 Yes
Lousley, J.E. [s.n.], United Kingdom K000790019 Yes
Baker, J.G. [s.n.], United Kingdom K000790065 Yes
Payne, R. [s.n.], United Kingdom K000790014 Yes
Hubbard, C.E. [s.n.], United Kingdom K000790053 Yes
Summerhayes, V.S. [836], United Kingdom K000790035 Yes
s.coll. [s.n.], United Kingdom K000790024 Yes
Summerhayes, V.S. [s.n.], United Kingdom K000790009 Yes
Williams, L.H. [s.n.], United Kingdom K000790012 Yes
Melville, R. [s.n.], United Kingdom K000790036 Yes
Loydell, A. [s.n.], United Kingdom K000790018 Yes
Brown, J. [s.n.], United Kingdom K000790046 Yes
Lousley, J.E. [s.n.], United Kingdom K000790045 Yes
Haines, D.M. [1], United Kingdom K000790010 Yes
Hosking, A. [s.n.], United Kingdom K000790040 Yes
s.coll. [s.n.], United Kingdom K000790044 Yes
Cole, L.W. [s.n.], United Kingdom K000790028 Yes
Horwood, A.R. [s.n.], United Kingdom K000790023 Yes
Makins, F.K. [2250], United Kingdom K000790008 Yes
Hubbard, C.E. [107], United Kingdom K000790052 Yes
Coates, J. [s.n.], United Kingdom K000790066 Yes
s.coll. [s.n.], United Kingdom K000790017 Yes
Prior, C.A. [s.n.], United Kingdom K000790057 Yes
Fraser, J. [s.n.], United Kingdom K000790026 Yes
T.W. [s.n.], United Kingdom K000790058 Yes
Townsend, C.C. [s.n.], United Kingdom K000790041 Yes
Webster, M.M. [5961], United Kingdom K000790033 Yes
Marshall, E.S. [s.n.], United Kingdom K000790007 Yes
s.coll. [334], United Kingdom K000790067 Yes
Jones, C. [s.n.], United Kingdom K000790020 Yes
Hubbard, C.E. [s.n.], United Kingdom K000790021 Yes
Oliver, D. [s.n.], United Kingdom K000790039 Yes
s.coll. [s.n.], United Kingdom K000790042 Yes
Hubbard, C.E. [s.n.], United Kingdom K000790050 Yes
T.M. [1369], United Kingdom K000790048 Yes
Jenner, J.H.A. [1600], United Kingdom K000790016 Yes

First published in Fl. Angl., ed. 2: 57 (1778)

Accepted by

  • Al-Rawi, A. (1987). Flora of Kuwait 2: 1-455. Alden Press Ltd., U.K.
  • Bor, N.L. (1968). Flora of Iraq 9: 1-588. Ministry of Agriculture & Agrarian Reform, Baghdad.
  • Bor, N.L. (1970). Flora Iranica 70: 1-573. Naturhistorisches Museums Wien.
  • Boulos, L. (2005). Flora of Egypt 4: 1-617. Al Hadara Publishing, Cairo.
  • Clayton, W.D., Harman, K.T. & Williamson, H. (2006). World Grass Species - Synonymy database The Board of Trustees of the Royal Botanic Gardens, Kew.
  • Danin, A. (2004). Distribution Atlas of Plants in the Flora Palaestina area: 1-517. The Israel Academy of Sciences and Humanities, Jerusalem.
  • Davis, P.H. (ed.) (1985). Flora of Turkey and the East Aegean Islands 9: 1-724. Edinburgh University Press, Edinburgh.
  • Dobignard, D. & Chatelain, C. (2010). Index synonymique de la flore d'Afrique du nord 1: 1-455. Éditions des conservatoire et jardin botaniques, Genève.
  • Fedorov, A.A. (ed.) (1999). Flora of Russia. The European part and bordering regions 1: 1-546. A.A. Balkema, Rotterdam, Broekfield.
  • Flora of North America Editorial Committee (2007). Flora of North America North of Mexico 24: 1-908. Oxford University Press, New York, Oxford.
  • Meikle, R.D. (1985). Flora of Cyprus 2: 833-1970. The Bentham-Moxon Trust Royal Botanic Gardens, Kew.
  • Takhtajan, A.L. (ed.) (2006). Konspekt Flora Kavkaza 2: 1-466. Editio Universitatis Petropolitanae.
  • Tutin, T.G. & al. (eds.) (1980). Flora Europaea 5: 1-452. Cambridge University Press.
  • Wilson, A. (ed.) (2009). Flora of Australia 44A: 1-410. Australian Government Publishing Service, Canberra.
  • Zuloaga, F.O., Morrone, O. , Belgrano, M.J., Marticorena, C. & Marchesi, E. (eds.) (2008). Catálogo de las Plantas Vasculares del Cono Sur Monographs in Systematic Botany from the Missouri Botanical Garden 107: 1-3348. Missouri Botanical Garden.

Literature

Kew Species Profiles

  • Alton, S. (2004). The Millennium Seed Bank Project (MSBP) International Programme. BGjournal 1: 15-16.
  • Cheffings, C. & Farrell, L. (eds) (2005). The Vascular Plant Red Data List for Great Britain. Joint Nature Conservation Committee, Peterborough.
  • Colmer, T. D., Flowers, T. J. & Munns, R. (2006). Use of wild relatives to improve salt tolerance in wheat. Journal of Experimental Botany 57: 1059-1078.
  • Cope, T. & Gray, A. (2009). Grasses of the British Isles. Botanical Society of the British Isles, London.
  • Hubbard, C. E. (1984). Grasses: a Guide to their Structure, Identification, Uses and Distribution in the British Isles. The Penguin Group, London.
  • Malik, A. I., English, J. P. & Coler T. D. (2009). Tolerance of Hordeum marinum accessions to O2 deficiency, salinity and these stresses combined. Annals of Botany 103: 237-248.
  • Speltzer (2009). Weed 2: Barley Grass.
  • Tropicos (2012). Hordeum marinum Huds.

Kew Backbone Distributions

  • Al-Rawi, A. (1987). Flora of Kuwait 2: 1-455. Alden Press Ltd., U.K.
  • Bor, N.L. (1968). Flora of Iraq 9: 1-588. Ministry of Agriculture & Agrarian Reform, Baghdad.
  • Boulos, L. (2005). Flora of Egypt 4: 1-617. Al Hadara Publishing, Cairo.
  • Cope, T.A. (1982). Flora of Pakistan 143: 1-678. Department of Botany, University of Karachi, Karachi.
  • Cope, T.A., Knees, S.G. & Miller, A.G. (2007). Flora of the Arabian peninsula and Socotra 5(1): 1-387. Edinburgh University Press.
  • Davis, P.H. (ed.) (1985). Flora of Turkey and the East Aegean Islands 9: 1-724. Edinburgh University Press, Edinburgh.
  • Dobignard, D. & Chatelain, C. (2010). Index synonymique de la flore d'Afrique du nord 1: 1-455. Éditions des conservatoire et jardin botaniques, Genève.
  • Edgar, E & Connor, H.E. (2010). Flora of New Zealand, ed. 2, 5: 1-650. R.E.Owen, Government Printer, Wellington.
  • Fedorov, A.A. (ed.) (1999). Flora of Russia. The European part and bordering regions 1: 1-546. A.A. Balkema, Rotterdam, Broekfield.
  • Fedtschenko, B.A. & al. (1932). Flora Turkmenii 1: 1-340. Turkmenskoe gosudarstvennoe izd., Ashkhabad.
  • Flora of North America Editorial Committee (2007). Flora of North America North of Mexico 24: 1-908. Oxford University Press, New York, Oxford.
  • Garcillán, P.P. & al. (2013). Plantas no nativas naturalizadas de la península de Baja California, México Botanical Sciences 91: 461-475.
  • Germishuizen, G. & Meyer, N.L. (eds.) (2003). Plants of Southern Africa: an annotated checklist. Strelitzia 14.: i-vi, 1-1231. National Botanical Institute, Pretoria.
  • Hassler, M. (2012). Flora of Rhodes. Systematic list of flora of Rhodes http://www.rz.uni-karlsruhe.de/~db111/flora/rhodos/list.php.
  • Koyama, T. (1987). Grasses of Japan and its neighboring regions: an identification manual: 1-570. Kodansha, Tokyo, Japan.
  • Meikle, R.D. (1985). Flora of Cyprus 2: 833-1970. The Bentham-Moxon Trust Royal Botanic Gardens, Kew.
  • Merkodovich, N.A. (ed.) (1941). Flora Uzbekistana 1: 1-566. Izd-va Akademii nauk Uzbekskoi SSR, Tashkent.
  • Ovczinnikov, P.N. (ed.) (1957). Flora Tadzhikskoi SSR 1: 1-547. Izd-vo Akademii nauk SSSR, Moskva.
  • Pavlov, N.V. (ed.) (1956). Flora Kazakhstana 1: 1-354. Alma-Ata, Izd-vo Akademii nauk Kazakhskoi SSR.
  • Roshevitz, R.J. & al. (eds.) (1950). Flora Kirgizskoi SSR 2: 1-315. Frunze : Izd-vo KirgizFAN SSSR.
  • Takhtajan, A.L. (ed.) (2006). Konspekt Flora Kavkaza 2: 1-466. Editio Universitatis Petropolitanae.
  • Tutin, T.G. & al. (eds.) (1980). Flora Europaea 5: 1-452. Cambridge University Press.
  • Werier, D. (2017). Catalogue of the Vascular plants of New York state Memoirs of the Torrey Botanical Club 27: 1-542. New York Botanical Garden.
  • Wilson, A. (ed.) (2009). Flora of Australia 44A: 1-410. Australian Government Publishing Service, Canberra.
  • Zuloaga, F.O., Morrone, O. , Belgrano, M.J., Marticorena, C. & Marchesi, E. (eds.) (2008). Catálogo de las Plantas Vasculares del Cono Sur Monographs in Systematic Botany from the Missouri Botanical Garden 107: 1-3348. Missouri Botanical Garden.

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  • Herbarium Catalogue Specimens

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  • Kew Backbone Distributions

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

  • Kew Species Profiles

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