Leymus arenarius
Beach rye ( Leymus arenarius )
The beach rye ( Leymus arenarius ), also called Blue Helmet, is a plant of the family Gramineae ( Poaceae ). It is often planted for fixing dunes, this rhizome are mostly used.
- 5.1 Notes and references
Description
Vegetative characteristics
The beach rye is a perennial herbaceous plant, forming large, gray-green to blue- gray colored clumps with long underground runners and many renovation sprouts. This sometimes grow up within the lowest leaf sheaths, usually they break through the leaf sheaths but with their buds. The stalks are 60 to 120, rarely to 200 cm high, erect and bare. The leaf sheaths are serrated, bare and open to the bottom. The ligule is a membranous fringe of up to one millimeter in length. The leaf blades are 20-60 cm long and 8 to 12, rarely up to 20 mm wide. They are spread out flat, even curled up in dry conditions. In vernation they are rolled. The leaves are stiff and pungent, at the top are on the ribs several rows of long spiked hair, making the surface appear rough. The underside is smooth. The blade has two sickle-shaped, hairless ears that are often bent upward.
Generative features
The inflorescence is a 15 to 30 cm long, dense and upright spike. The spikelets are sessile and are usually in pairs on the rachis, in the middle of the ear as well as a trio. The spikelets contain three to four (rarely six) petals and are 20 to 30 mm long. The glumes are similar, three annoying, 20 to 30 mm long, from lanceolate, pointed shape. You are derbhäutig and have a keel, which is ciliated scattered. The lemmas having seven nerve 15 to 25 mm long, with the top being shorter than the lower. Their shape is sharp wide - lanceolate, they are derbhäutig and densely covered with short. The palea are two annoying and as long as the lemmas. They are lanceolate and short hair on the keels. The dust bags are 7-8 mm long. The flowering period extends from June to August.
The caryopses are 6-8 mm long and hairy at the top. You are intergrown with deck and palea. When ripe spikelets disintegrate on the glumes and between the florets, stop the glumes.
The chromosome number is 2n = 56
Ecology
The beach rye is a rhizome - Geophyt and a blue-green by wax coating, very massive, long streamers forming grass. Vegetative reproduction occurs abundantly through the foothills up to several meters long. The stiff, stinging, curled leaves are pronounced drought adapted, so Xeromorph; their coarseness also prevents them from being eroded by ungulates.
Pollination is accomplished by the wind.
Diasporas ( unit propagation ) are covered by the remaining husks caryopses. They spread as Regenschwemmling out, or they are subject to the propagation swimming in the sea; next processing propagation is done by birds and wind propagation.
Occurrence
The beach rye is native to the coasts of western and northwestern Europe. In many other areas it has been introduced.
In Germany the beach rye on the coasts of North and Baltic Sea is widespread. In the interior it is sometimes planted.
It grows along the coasts in the region of the upper Spülsaums, at the foot of cliffs, on the barrier beach, dunes and Vordünen. He is also naturalized on the stone packs of dikes, inland dunes and in the places of Geest Islands. It grows mostly on loose sand dunes. It is easy to nitrogen- loving and tolerate salt. He is a pioneer foothills and a light plant. It grows up together with the dunes and fixed it the sand.
Phytosociological the beach rye is a weak Assoziationscharakterart the beach oats and white sand dunes companies ( Elymo - Ammophiletum arenariae ).
Diseases
The beach rye is often attacked by the smut fungus Ustilago hypodytes. On the stalks no more spikes are formed in their place created thick layers of black fungal spores.
Swell
- H. J. Conert: Pareys grasses book. Identify and determine the grasses Germany. Blackwell Scientific Publishers, Berlin, Vienna 2000, p 84 ISBN 3-8263-3327-6
- Beach rye. In: FloraWeb.de.