Annual bluegrass
| Annual bluegrass | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Annual bluegrass ( Poa annua ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Poa annua | ||||||||||||
| L. |
The annual bluegrass ( Poa annua ) is probably the most widespread and most common sweet grass of all. While the other species of the genus of the bluegrass ( Poa ) are perennial herbaceous plants , this one is annual , but it can also overwinter under favorable circumstances.
description
.jpg)
Vegetative characteristics
The annual bluegrass grows as an annual herbaceous plant and forms small clumps that are comparatively small with heights of 5 to a maximum of 30 centimeters, but mostly 10 to 15 centimeters. The stalks are prostrate and then ascending with a few kinks at the stalk nodes. To the node ( Nodien to roots can form).
The light green to green leaves are divided into leaf sheath and leaf blade. The white ligule is 2 to 4 millimeters long and runs down to the vagina. The simple leaf blade is 2 to 5 millimeters wide and has a short, characteristic boat-shaped tip.
Generative characteristics
The loosely spread, sometimes one-sided, paniculate inflorescence is rarely longer than 5 centimeters. The panicle branches are often in pairs. The spikelets are four or more flowered, 2 to 5 millimeters long, green or rarely tinged purple. The lower glume is one-nerved, the upper three-nerved. The panicles are formed all year round if the weather is suitable.
The caryopses are from the permanent, stiff-haired husks surrounded
The number of chromosomes is 2n = 28.
ecology
The annual bluegrass is a summer or winter annual therophyte or a perennial clump plant.
There is self-pollination as well as wind pollination according to the "long dust thread type". The annual bluegrass has no blooming period and is therefore also a snow bloomer. Annual forms of the species can bloom after 45 to 60 days.
The year-round ripening caryopses are only 0.2 to 0.4 mg in weight. Usually the tread spreads (as watery). In addition, people spread , spread by birds , as wind spreaders and balloon flyers , digestive spread and spread by ants (e.g. lawn ants ). Fruit ripening begins in May. The caryopses are light germs .
The annual bluegrass is not eaten by cattle because of its small size as long as there are still tall forage plants. Its presence on pastures therefore indicates overgrazing .
Occurrence
Annual bluegrass is a cosmopolitan species . In the tropics it grows mainly in the mountains. It is one of the few seed plants that can also be found in the Antarctic , but has only been here for a few decades.
The annual bluegrass is common everywhere from the lowlands to the high mountains on roadsides, in pavement cracks , gardens, fields, stepways . It is the character of turf societies (Polygono-Poetea). It thrives best in nitrogen-rich, heavy soils , but will also grow in sandy soil. They can be found in city centers as well as in natural areas.
Others
In 1957, Thomas Gaskell Tutin found out through genetic experiments that the annual bluegrass is an allo tetraploid species that emerged from spring bluegrass (Poa infirma) and lager bluegrass (Poa supina).
literature
- Henning Haeupler , Thomas Muer: picture atlas of the fern and flowering plants of Germany (= the fern and flowering plants of Germany. Volume 2). Published by the Federal Agency for Nature Conservation. Ulmer, Stuttgart 2000, ISBN 3-8001-3364-4 .
- Werner Rothmaler : Excursion flora for the areas of the GDR and the FRG . Volume 2: Vascular Plants, 14th Edition. People and knowledge, Berlin 1988, ISBN 3-060-12539-2 .
- Otto Schmeil , Jost Fitschen , Werner Rauh : Flora of Germany and its adjacent areas . 84th edition. Quelle & Meyer, Heidelberg 1968.
- Dietmar Aichele, Heinz-Werner Schwegler: Our grasses . 7th edition. Franckh'sche Verlagsbuchhandlung, Kosmos-Naturführer, Stuttgart 1984, ISBN 3-440-05284-2 .
- Grassland online - overgrazing.
- Guanghua Zhu, Liang Liu, Robert J. Soreng, Marina V. Olonova: Poa. : Poa annua , p. 263 - online with the same text as the printed work , In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Ed.): Flora of China. Volume 22: Poaceae , Science Press and Missouri Botanical Garden Press, Beijing and St. Louis 2006, ISBN 1-930723-50-4 .
- 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
- ↑ a b Poa annua L., Annual bluegrass. In: FloraWeb.de.
- ^ Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Stuttgart, Verlag Eugen Ulmer, 2001. ISBN 3-8001-3131-5 . Page 222.
- ^ Thomas Gaskell Tutin : A contribution to the experimental taxonomy of Poa annua L. In: Watsonia , Volume 4, 1957, pp. 1-10.
Web links
- Annual bluegrass . In: BiolFlor, the database of biological-ecological characteristics of the flora of Germany.
- Profile and distribution map for Bavaria . In: Botanical Information Hub of Bavaria .
- Poa annua L. In: Info Flora , the national data and information center for Swiss flora . Retrieved September 24, 2015.
- Distribution in the northern hemisphere according to: Eric Hultén , Magnus Fries: Atlas of North European vascular plants 1986, ISBN 3-87429-263-0 .
- Thomas Meyer: Data sheet with identification key and photos at Flora-de: Flora von Deutschland (old name of the website: Flowers in Swabia )
- Data sheet with photo and distribution in France at Tela Botanica .
- Poa annua onthe IUCN 2013 Red List of Threatened Species . 2. Posted by: N. Brummitt, 2012. Retrieved April 8, 2014.
