Two-line blue grass

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Two-line blue grass
Two-line blue grass (Oreochloa disticha)

Two-line blue grass ( Oreochloa disticha )

Systematics
Monocots
Commelinids
Order : Sweet grass (Poales)
Family : Sweet grasses (Poaceae)
Genre : Oreochloa
Type : Two-line blue grass
Scientific name
Oreochloa disticha
( Wulfen ) Link

The two-line blue grass ( Oreochloa disticha ), also called two-line head grass , is a plant species within the sweet grass family (Poaceae).

description

Illustration from Atlas of Alpine Flora
inflorescence

Vegetative characteristics

The two-line blue grass is a presumably summer green, perennial herbaceous plant and reaches heights of 10 to 20 centimeters. It forms small but dense clumps with numerous renewal shoots that grow up within the lowest leaf sheaths. The stalks are erect, thin and stiff and rough or hairy under the inflorescence.

The leaf sheaths are initially closed up to the top, but soon tear open. The leaves of the renewal shoot are 5–15 cm long and 0.3–0.6 millimeters wide, folded like a bristle and hairy.

Generative characteristics

The flowering period extends from July to August. In a short, spike-shaped, raceme inflorescence are strictly two-line and the spikelets are arranged individually on the axis. The spindle is 0.7 to 1.5 inches long and visible from the side. The lower panicle branches have no bract . The spikelets contain three to five flowers and are 4–5.5 mm long. The awn of the lemma is short. The florets fall out individually from the remaining glumes when they ripen. The back of the lemmas is green or straw-colored and surrounded by a broad blue-violet border. The palea is about as long as the lemma. The anthers are 1.5–2 mm long.

The number of chromosomes is 2n = 14.

ecology

The two-line blue grass is a hemicryptophyte .

Occurrence

Two-line blue grass ( Oreochloa disticha ) in the Tatra Mountains
Two-line blue grass ( Oreochloa disticha ) in the Hohe Tauern

The two-line blue grass is widespread in the silicate areas of the mountains of Central and Southern Europe as far as Ukraine. In Germany it occurs only in southwest Bavaria in the Allgäu in Himmelsjoch, Kreuzeck and Laufbacher Eck . In Austria, this grass is widespread in the federal states of Vorarlberg , Tyrol , Salzburg, Carinthia and Styria from the alpine to subnival altitude level . In the Allgäu Alps it occurs above 2000 meters above sea level.

As a location, wind-exposed, gappy breeds with short snow cover on acidic, dry, open raw soils are preferred. The main occurrence of the two-row blue grass lies in crooked sedge grass ( Caricetum curvulae ), which is considered to be associated with it. It also grows in dwarf shrub heaths .

Taxonomy

It was first published in 1781 under the name ( Basionym ) Poa disticha by Franz Xaver von Wulfen . The new combination to Oreochloa disticha (Wulf.) Link was published by Heinrich Friedrich Link . Other synonyms are Sesleria disticha (Wulf.) Pers. The generic name Oreochloa is derived from the Greek words ὄρος (óros) for mountain and χλόη (chlóe) for young green, grass. The specific epithet disticha is derived from the Greek and means two years.

supporting documents

  • Eckehart J. Jäger, Klaus Werner (Ed.): Excursion flora from Germany . Founded by Werner Rothmaler. 10th edited edition. tape 4 : Vascular Plants: Critical Volume . Elsevier, Spektrum Akademischer Verlag, Munich / Heidelberg 2005, ISBN 3-8274-1496-2 .
  • Oreochloa disticha (Wulfen) Link, two-line head grass. In: FloraWeb.de. , last accessed on September 27, 2015
  • Oskar Angerer, Thomas Muer: Alpine plants (=  Ulm nature guide ). Eugen Ulmer, Stuttgart (Hohenheim) 2004, ISBN 3-8001-3374-1 .
  • Manfred A. Fischer, Wolfgang Adler, Karl Oswald: Excursion flora for Austria, Liechtenstein and South Tyrol . 2nd, improved and enlarged edition. State of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2005, ISBN 3-85474-140-5 .
  • Hans Joachim Conert: Oreochloa . In: Gustav Hegi : Illustrated flora of Central Europe . 3rd ed., Volume I, Part 3, pages 471-473. Verlag Paul Parey, Berlin, Hamburg, 1987. ISBN 3-489-52320-2 (description)

Individual evidence

  1. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . With the collaboration of Angelika Schwabe and Theo Müller. 8th, heavily revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 2001, ISBN 3-8001-3131-5 , pp.  229 .
  2. ↑ Rafaël Govaerts (ed.): Oreochloa disticha. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved November 11, 2016.
  3. ↑ a b Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 174.
  4. ↑ Helmut Genaust: Etymological dictionary of botanical plant names . 3. Edition. Nikol, Hamburg 2012, ISBN 978-3-86820-149-9 (reprint from 1996).

Web links

Commons : Two-line blue grass ( Oreochloa disticha )  - album with pictures, videos and audio files