| Elymus repens subsp. repens | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Monocots |
| (unranked): | Commelinids |
| Order: | Poales |
| Family: | Poaceae |
| Genus: | Elymus |
| Species: | E. repens |
| Binomial name | |
| Elymus repens (L.) Gould |
|
Elymus repens (L.) Gould (couch grass; syn. Triticum repens L., Agropyron repens (L.) P. Beauv., Elytrigia repens (L.) Desv. ex Nevski) is a very common perennial species of grass native to most of Europe, Asia, and northwest Africa. Other names include twitch, quick grass, quitch grass (also just quitch), dog grass, quackgrass, scutch grass, and witchgrass.[1][2][3][4]
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It has creeping rhizomes which enable it to grow rapidly across grassland. 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.[2][3][5]
[6].
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:[1][2][3]
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.).[2]
The foliage is an important forage grass for many grazing mammals.[3] The seeds are eaten by several species of grassland birds, particularly buntings and finches.[7] The caterpillars of some Lepidoptera use it as a foodplant, e.g. the Essex Skipper (Thymelicus lineola).
Couch Grass has become naturalised throughout much of the world, and often listed as an invasive weed.[1] It is very difficult to remove from garden environments,as each piece of rhizome can develop into a new plant. One 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.
Couch Grass has been used in herbal medicine since the Classical Greek period. Sick dogs are known to dig up and eat the root, and mediaeval herbalists used it to treat inflamed bladders, painful urination and water retention. It also has antiseptic properties.[8][9]
The dried rhizomes of couch grass were broken up and used as incense in mediaeval Northern Europe where other resin-based types of incense were unavailable.