Elymus (genus)

Couch Grass or Creeping couch grass ( Elymus repens ), illustration

The couch grass ( Elymus ), also hair barley, are a genus of flowering plants in the family of grasses ( Poaceae ).

Description of the plant

In Elymus species are perennial herbaceous plants. Some species form long underground rhizomes, which can re- rooted at each node, so that even small cuts can produce new plants.

There are ears grasses. The three-to achtblütigen spikelets are arranged in two rows in slender spikes, where they turn their broadside of the ears axis. You stand upright stiff and are pressed against the ears axis. Most species are more or less grannenlos, but there are also species with short awns.

Distribution and site conditions

Mercury species are found in all regions of the northern hemisphere temperate, also in southern South America.

Many species prefer more or less open locations such as sandy soils, waste places, gravel corridors or dry grasslands. The nutrient requirement varies greatly from species to species.

Etymology

The term " couch grass " comes from the Old High German word for quicksilver " strong ", " alive " and indicates the strong urge to spread and the difficulty of addressing a number of styles.

System

The genus Elymus consists of about 40 to 100 species, depending on the view. Sometimes they are divided, however, depending on the existence of rhizomes in two genera, the dog couch grass ( Roegneria ) with the vast number of species without rhizomes, and Genuine couch grass ( Elytrigia ) on.

Types (selection)

In Central Europe are, inter alia, the following methods:

  • Sand couch grass ( Elymus arenosus ( Spenn. ) Conert ): Used mainly before on the coast in north-western Europe; in Germany only on the " Mainzer Sand".
  • Dune couch grass or sealing -spiked wheatgrass, sometimes called beach - couch grass ( Elymus athericus (Link) Kerguélen ): In Central Europe on warm dry sites in the German - Swiss border, in Baden, in Alsace, in the south of Switzerland, in the Vinschgau and at the North and the Baltic Sea coast, otherwise on the coasts of Europe and the Near East, is naturalized in North America
  • Dog- wheatgrass ( Elymus caninus (L.) L.): Comes in thickets or forest edges in Europe and Asia before and is naturalized in North America and New Zealand
  • Rushes Wheatgrass, also beach - couch grass (see above) or even beach wheat called ( Elymus farctus ( viv ) Runemark ex Melderis ): This species grows on sandy soils, and in particular dunes and solidified by their extensive network of robust rhizomes the floor and holding flood sand fixed. This is involved in the development of Vordünen. It occurs in Europe, North Africa, Western Asia and naturalized in North America before.
  • Grey-green couch grass ( Elymus hispidus ( Opiz ) Melderis ); arrives in Europe and front to Central Asia before
  • Elymus intermedius: comes, among others in Switzerland before in some places in the Valais, Ticino and Graubünden.
  • Stumpfblütige couch grass ( Elymus obtusiflorus ( DC.) Conert ): Descended originally from South East Europe and Turkey, but naturalized in Europe and North America, mainly on roadsides.
  • Elymus repens (L.) Gould: Creep couch grass or Couch Grass ( Elymus repens ssp repens. ): A widespread and common weed plant that grows in Europe, North Africa, North America and Siberia
  • Beach Creep couch grass ( Elymus repens ssp littoreus. ): Only on the coasts.

Other species outside of Central Europe ( selection):

  • Canada - couch grass ( Elymus canadensis L.); occurs in Canada, Alaska and the U.S.
  • Elymus magellanicus ( Desv. ) Á. Löve; occurs in the mountains of South America
  • Elymus trachycaulus (Link) Gould ex Shinners; Occurs in East Asia and North America to Mexico
  • Bobwhite couch grass ( Elymus virginicus L.); occurs in Canada and the U.S.

In addition, several hybrids are described below:

  • Lockerblütige bastard couch grass ( Elymus × laxus (Fr.) Melderis & DCMcClint. )
  • Bastard - rushes - couch grass ( Elymus × obtusiusculus ( Lange) Melderis & DCMcClint. )
  • Bastard Creep couch grass ( Elymus × oliveri ( Druce ) Melderis & DCMcClint. )

Another European " couch grass " type (but outside Germany ) is the

  • Comb wheatgrass ( Agropyron cristatum (L.) Gaertn. ).

The types differ in, among other things, whether they are of foothills and is designed as the shape of the glumes.

  • For synonym: Elymus arenarius Leymus arenarius see now
Pooideae Triticeae Otto Schmeil Jost Fitschen Werner Rauh
289323
de