Elymus repens

Familia: Poaceae
Subfamilia: Pooideae
Tribus: Hordeeae
Subtribus: Hordeinae
Genus: Elymus
Species: Elymus repens
Subspecies: E. r. subsp. arenosus – E. r. subsp. atlantis – E. r. subsp. calcareus – E. r. subsp. repens
Name

Elymus repens (L.) Gould (1947)
Synonyms

Basionym:

Triticum repens L., Sp. Pl. 86. 1753.

Homotypic:

Agropyron junceum var. repens (L.) T.Marsson, Allg. Bot. Z. Syst. 7: 154. 1901.
Agropyron repens (L.) P.Beauv., Ess. Agrostogr. 102. 1812.
Braconotia officinarum Godr., Fl. Lorraine 3: 192. 1844, nom. superfl.
Elytrigia repens (L.) Nevski, Trudy Bot. Inst. Akad. Nauk S.S.S.R., Ser. 1, Fl. Sist. Vyssh. Rast. 1: 14. 1933.
Frumentum repens (L.) E.H.L.Krause, Bot. Centralbl. 73: 340. 1898.
Triticum infestum Salisb., Prodr. Stirp. Chap. Allerton 27. 1796, nom. superfl.
Zeia repens (L.) Lunell, Amer. Midl. Naturalist 4: 227. 1915.

References

Gould 1947: Madroño 9: 127.
Govaerts, R. et al. 2013. Elymus repens in World Checklist of Selected Plant Families. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the internet. Accessed: 2013 April 11. Reference page.
USDA, ARS, Germplasm Resources Information Network. Elymus repens in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service.

Vernacular names
беларуская: Пырнік паўзучы
Deutsch: Gemeine Quecke
English: Quackgrass
suomi: Juolavehnä
magyar: Tarackbúza
italiano: Gramigna
lietuvių: Paprastasis varputis
македонски: Пиреј
Nederlands: Kweek
polski: Perz właściwy
русский: Пырей ползучий
Türkçe: Ayrık otu
Links

Elymus repens, commonly known as couch grass, is a very common perennial species of grass native to most of Europe, Asia, the Arctic biome, and northwest Africa. It has been brought into other mild northern climates for forage or erosion control, but is often considered a weed.

Other names include common couch,[1] twitch, quick grass, quitch grass (also just quitch), dog grass, quackgrass, scutch grass, and witchgrass.[2][3][4][5]

Description

It has creeping rhizomes which enable it to grow rapidly across grassland. It has flat, hairy leaves with upright flower spikes. The stems ('culms') grow to 40–150 cm tall; the leaves are linear, 15–40 cm long and 3–10 mm broad at the base of the plant, with leaves higher on the stems 2–8.5 mm broad. The flower spike is 10–30 cm long, with spikelets 1–2 cm long, 5–7 mm broad and 3 mm thick with three to eight florets. The glumes are 7–12 mm long, usually without an awn or with only a short one.

It flowers at the end of June through to August in the Northern Hemisphere.[3][4][6][7]

Taxonomy

Various taxonomic subdivisions of this species have been proposed. Moreover, it is assigned to various genera (Elymus, Elytrigium, Agropyron). In a recent classification, three subspecies are distinguished, one of these with an additional variety:[2][3][4]

Elytrigia repens subsp. repens. Throughout most of the range of the species.
Elytrigia repens subsp. repens var. repens. Awns usually absent or if present, very short.
Elytrigia repens subsp. repens var. aristata (Döll) P.D.Sell. Awns present, up to 15 mm long.
Elytrigia repens subsp. elongatiformis (Drobow) Tzvelev (syn. Elytrigia elongatiformis (Drobow) Nevski). Central and southwestern Asia, far southeastern Europe (Ukraine).
Elytrigia repens subsp. longearistata N. R. Cui. Western China (Xinjiang).

Hybrids are recorded with several related grasses, including Elytrigia juncea (Elytrigia × laxa (Fr.) Kerguélen), Elytrigia atherica (Elytrigia × drucei Stace), and with the barley species Hordeum secalinum (× Elytrordeum langei (K. Richt.) Hyl.).[3]
Ecology

The foliage is an important forage grass for many grazing mammals.[4] The seeds are eaten by several species of grassland birds, particularly buntings and finches.[8] The caterpillars of some Lepidoptera use it as a foodplant, e.g. the Essex skipper (Thymelicus lineola).
Eradication

Couch grass has become naturalised throughout much of the world, and is often listed as an invasive weed.[2] It is very difficult to remove from garden environments, as the thin rhizomes become entangled among the roots of shrubs and perennials, and each severed piece of rhizome can develop into a new plant. It may be possible to loosen the earth around the plant, and carefully pull out the complete rhizome. This is best done in the spring, when disturbed plants can recover.[9][10] Another method is to dig deep into the ground in order to remove as much of the grass as possible. The area should then be covered with a thick layer of woodchips. To further prevent re-growth, cardboard can be placed underneath the woodchips. The long, white rhizomes will, however, dry out and die if left on the surface. Many herbicides will also control it.
Applications

The dried rhizomes of couch grass were broken up and used as incense in medieval northern Europe where other resin-based types of incense were unavailable. Elymus repens (Agropyron repens) rhizomes have been used in the traditional Austrian medicine against fever, internally as a tea, syrup, or cold maceration in water, or externally applied as a crude drug.[11]
References

BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
"Elymus repens subsp. repens". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2017-12-15.
Flora of NW Europe: Elytrigia repens
Flora of China: Elytrigia repens
Webster Third International Dictionary (Könemann, 1993) ISBN 3-8290-5292-8
Fitter, R., Fitter, A., & Farrer, A. (1984). Collins Guide to the Grasses, Sedges, Rushes and Ferns of Britain and Northern Europe. Collins ISBN 0-00-219128-8.
Hubbard, C. E. Grasses. Penguin Books, 1978
Snow, D. W. & Perrins, C. M. (1998). The Birds of the Western Palearctic Concise Edition. OUP ISBN 0-19-854099-X.
"Couch grass / Royal Horticultural Society". Apps.rhs.org.uk. 2012-02-27. Archived from the original on 2012-10-07. Retrieved 2012-10-13.
Hessayon, Dr D. G. (2007). The pest & weed expert. United Kingdom: Expert. p. 128. ISBN 978-0903505628.
Vogl, S; Picker, P; Mihaly-Bison, J; Fakhrudin, N; Atanasov, A. G.; Heiss, E. H.; Wawrosch, C; Reznicek, G; Dirsch, V. M.; Saukel, J; Kopp, B (2013). "Ethnopharmacological in vitro studies on Austria's folk medicine--an unexplored lore in vitro anti-inflammatory activities of 71 Austrian traditional herbal drugs". Journal of Ethnopharmacology. 149 (3): 750–71. doi:10.1016/j.jep.2013.06.007. PMC 3791396. PMID 23770053.