Silver ragweed

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Silver ragweed
Silver ragweed (Achnatherum calamagrostis)

Silver ragweed ( Achnatherum calamagrostis )

Systematics
Commelinids
Order : Sweet grass (Poales)
Family : Sweet grasses (Poaceae)
Subfamily : Pooideae
Genre : Achnatherum
Type : Silver ragweed
Scientific name
Achnatherum calamagrostis
( L. ) P.Beauv.

The silver ragweed ( Achnatherum calamagrostis ), also called ragweed for short , is a species of the genus Achnatherum in the sweet grass family (Poaceae).

description

Vegetative characteristics

The silver ragweed is a perennial herbaceous plant that reaches heights of 40 to 120 centimeters. It is clumping. The leaves are divided into leaf sheath and leaf blade. The grooved leaf sheath is smooth and glabrous and set off from the leaf blade by a conspicuous line. The ligula is a collar-shaped, membranous hem about 0.5 millimeters long. The simple leaf blade is up to 60 centimeters long and up to 8 millimeters wide, spread out flat, rough on the upper side and on the edges, smooth on the underside.

Generative characteristics

The flowering period extends from June to September. The dense, paniculate inflorescence is 20 to 30 centimeters long and 4 to 6 centimeters wide in outline, lanceolate, upright or slightly nodding. Three to seven side branches go from the main axis in clusters and are occupied with more than ten spikelets. The spikelets are single-flowered, 7 to 9 millimeters long without awn, light green to straw-colored and shiny. The glumes are almost equal to each other and 7 to 9 millimeters long. The shaggy, silky hairy lemma is five-nerved and 3 to 4 millimeters long, slightly notched at the upper end and awned between the side lobes, rough on the back and in the uppermost part. The awn is 8 to 12 millimeters long, curved sickle-shaped in the lower part and bare, but rough.

The number of chromosomes is 2n = 24, less often 44.

ecology

The silver ragweed is a hemicryptophyte .

Occurrence

The silver ragweed is widespread in Central and Southern Europe before and from Central Asia to Siberia and China and occurs in Morocco . In Central Europe it thrives in sunny stone rubble lawns on dry to moderately fresh, lime-rich, low-humus, partly marl-containing, loose, agitated fine rubble or rocky soils . It is a characteristic species of Stipetum calamagrostis from the Association Stipion calamagrostis, comes as Schwemmling in plant communities of the Association Epilobion fleischeri or ledge companies of the Association Potentillion caulescentis ago. In Germany it occurs only in the Alps , in the Alpine foothills and in the Danube breakthrough valley of the Swabian Alb. In the Allgäu Alps in Bavaria, near the Oytalhaus and on the glide path , it rises to an altitude of 1280 meters. The silver rogue grass is a debris dam and debris stabilizer .

Taxonomy

The first publication took place in 1759 under the name ( Basionym ) Agrostis calamagrostis by Carl von Linné . The new combination to Achnatherum calamagrostis (L.) P.Beauv. was published in 1812 by Ambroise Marie François Joseph Palisot de Beauvois . Other synonyms for Achnatherum calamagrostis (L.) P.Beauv. are: Stipa calamagrostis (L.) Wahlenb. , Lasiogrostis calamagrostis (L.) Link .

The genus Achnatherum includes, broadly speaking, about 20 Eurasian, 35 North American and one New Zealand species, the center of distribution of the Eurasian species is China. According to recent findings, the genus delimited in this way is not a monophyletic unit. Achnatherum calamagrostis belongs to a monophyletic species group that is summarized as the Achnatherum section Achnatherum (syn .: Stipa sect. Lasiagrostis ). This is only common in Eurasian.

literature

  • Hans Joachim Conert: Stipa. In: Gustav Hegi : Illustrated flora of Central Europe. 3rd ed., Volume I, Part 3, pages 396-426. Paul Parey Publishing House, Berlin, Hamburg, 1992, ISBN 3-489-52520-5 .

Individual evidence

  1. ↑ a b c d e f Achnatherum calamagrostis (L.) P. Beauv., Silber-Raugras. In: FloraWeb.de.
  2. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Stuttgart, Verlag Eugen Ulmer, 2001, ISBN 3-8001-3131-5 , p. 261.
  3. ↑ Rafaël Govaerts (ed.): Achnatherum calamagrostis. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved November 25, 2016.
  4. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 152.
  5. ↑ Konstantin Romaschenko, Paul M. Peterson, Robert J. Soreng, Nuria Garcia-Jacas, Oksana Futorna, Alfonso Susanna (2012): Systematics and evolution of the needle grasses (Poaceae: Pooideae: Stipeae) based on analysis of multiple chloroplast loci, ITS, and Lemma Micromorphology. Taxon 61 (1): 18-44.

Web links

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