Trident

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Trident
Trident (Danthonia decumbens)

Trident ( Danthonia decumbens )

Systematics
Monocots
Commelinids
Order : Sweet grass (Poales)
Family : Sweet grasses (Poaceae)
Genre : Danthonia
Type : Trident
Scientific name
Danthonia decumbens
( L. ) DC.
Stem with leaf sheath, hairline and ligule
Trident ( Danthonia decumbens )
Caryopsis encased in cover (Lem) and palea (Pal) The lemma has a tridentate tip.

The three-toothed tooth ( Danthonia decumbens ) is a species of the sweet grass family (Poaceae). The nominate form Danthonia decumbens ssp. decumbens is called Common Trident ; in addition, since 1977 Danthonia decumbens ssp. decipiens - Rasiger Dreizahn - understood as an independent clan.

description

The subspecies decumbens reaches heights of 15 to 50 centimeters, grows in dense lawns and has upright to ascending, sturdy, compact stalks. The subspecies decipiens is a bit taller, has rather loose grass and has delicate, slender stalks. The ligule is formed as a lash line; the leaf sheaths are also long ciliate at the edges. The inflorescence is a loose cluster of 4 to 6 cm long , contracted to form a false ear and consists of 4 to 12 spikelets . These are each 6–12 mm long, are shiny, whitish-green and often tinged with violet on the husks. Each spikelet has two to five flowers. The lemmas are three-toothed, which is what the German name refers to.

The chromosome number of the species is 2n = 36, but also 18, 24 or 124.

ecology

The three-toothed tooth is a persistent, mostly densely grassed hemicryptophyte . It forms a VA mycorrhiza .

Most of the flowers do not open due to a lack of erectile tissue , so they show celestogamy . There are also individual flowers that open with the erectile tissue, their anthers are 1 to 2 mm long. Flowering time is from June to July.

Diaspore (expansion unit) is the caryopsis surrounded by the cover and palea , it is boat-shaped and hairy at the base. It is subject to the spread of ants and spreads as a rain swallow and water-like.

Occurrence and location requirements

The distribution area of ​​the trident extends from Europe and the Mediterranean area to the Caucasus and Macaronesia .

The Dreizahn mainly inhabits poor and semi- arid grasslands . It can be found in dwarf shrub heaths , grass lawns , fresh meadows and pastures. It grows less frequently in wet meadows . It is a Nardo-Callunetea class character in Central Europe.

The subspecies Danthonia decumbens subsp. decipiens O.Schwarz & Bässler prefers alkaline, calcareous locations. It occurs in Molinion and Mesobromion societies.

In the Allgäu Alps it rises (after Wengenmayr) at the summit of Fürschießer in Bavaria up to 2250 m above sea level.

literature

  • Henning Haeupler, Thomas Muer: picture atlas of the fern and flowering plants of Germany . Ed .: Federal Agency for Nature Conservation (=  The fern and flowering plants of Germany . Volume 2 ). Eugen Ulmer, Stuttgart (Hohenheim) 2000, ISBN 3-8001-3364-4 .
  • 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 .
  • Dietmar Aichele, Heinz-Werner Schwegler: Our grasses. Sweet grasses, sour grasses, rushes . 11th edition. Kosmos, Stuttgart 1998, ISBN 3-440-07613-X .
  • Ruprecht Düll , Herfried Kutzelnigg : Pocket dictionary of plants in Germany and neighboring countries. The most common Central European species in portrait. 7th, corrected and enlarged edition. Quelle & Meyer, Wiebelsheim 2011, ISBN 978-3-494-01424-1 .

Individual evidence

  1. ↑ a b c Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Stuttgart, Verlag Eugen Ulmer, 2001. ISBN 3-8001-3131-5 . Pages 247–248.
  2. ↑ Rafaël Govaerts (Ed.): Danthonia decumbens. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved November 17, 2016.
  3. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 173.

Web links

Commons : Danthonia decumbens  - album with pictures, videos and audio files