''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,
twitch, quick grass, quitch grass (also just quitch), dog grass, quackgrass, scutch grass, and witchgrass.
[Flora of NW Europe]
''Elytrigia repens''
/ref>[Flora of China]
''Elytrigia repens''
/ref>
Description
It has creeping rhizome
In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
s 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
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
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
AWN may stand for:
* Awn Access to Justice Network in Gaza Strip, Legal Aid Network operate in Gaza Strip, Palestine
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* Avant Window Navigator, a dock-like bar that tracks open windows ...
or with only a short one.
It flowers at the end of June through to August in the Northern Hemisphere.[Fitter, R., Fitter, A., & Farrer, A. (1984). ''Collins Guide to the Grasses, Sedges, Rushes and Ferns of Britain and Northern Europe''. Collins .]
File:Elymus.repens.jpg, Flower spike
Image:Kweek ligula Elytrigia repens.jpg, Blunt ligule 1mm high, also showing a few very fine hairs of the plant
Image:Kweek blad Elytrigia repens.jpg, Showing the leaf is dull green, mainly parallel, with auricles and ribbed
Image:Kweek rizomen Elytrigia repens.jpg, Rhizomes
Image:Kweek Elytrigia repens.jpg, Showing general tufted and visual appearance of the plant
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
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
are distinguished, one of these with an additional variety:[
*''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.).][
]
Ecology
The foliage is an important forage grass for many grazing mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s.[ The seeds are eaten by several species of grassland birds, particularly buntings and finches.][Snow, D. W. & Perrins, C. M. (1998). ''The Birds of the Western Palearctic'' Concise Edition. OUP .] The caterpillar
Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths).
As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...
s of some Lepidoptera
Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...
use it as a foodplant, e.g. the Essex skipper (''Thymelicus lineola'').
Eradication
Couch grass has become naturalised
Naturalization (or naturalisation) is the legal act or process by which a non-citizen of a country may acquire citizenship or nationality of that country. It may be done automatically by a statute, i.e., without any effort on the part of the in ...
throughout much of the world, and is often listed as an invasive weed
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...
.[ 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
In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
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. 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
In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
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.
References
External links
Species Profile- Quackgrass (''Elymus repens'')
National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Quackgrass.
{{Taxonbar, from=Q276262
repens
''Eprius'' is a genus of skipper butterflies in the family Hesperiidae.
Species
*''Eprius repens'' Evans, 1955
*''Eprius repta'' Evans, 1955
*''Eprius veleda
''Eprius'' is a genus of skipper butterflies in the family Hesperiidae.
Species ...
Medicinal plants of Africa
Butterfly food plants
Medicinal plants of Asia
Medicinal plants of Europe
Plants described in 1753
Taxa named by Carl Linnaeus