Flat-stemmed pondweed
| Flat-stemmed pondweed | ||||||||||||
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Flat-stemmed pondweed ( Potamogeton compressus ) |
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| Potamogeton compressus | ||||||||||||
| L. |
The submerged living Flachstängelige pondweed ( Potamogeton compressus ) is a perennial representative of the family of potamogetonaceae (Potamogetonaceae). The flat-stemmed pondweed flowers underwater between June and September. Its flowers are also pollinated under water ( hydrophilicity ). Its fruits, which are provided with a small hump, are also spread out through the water ( hydrochory ).
Occurrence
The flat-stemmed spawning herb, which is severely endangered in Germany by eutrophication and water pollution, occurs in meso- to eutrophic, stagnant or slow-flowing waters. In Germany it is on the red list of vascular plants and has become very rare in places. Otherwise it occurs in the temperate latitudes of Eurasia. It is a character species of the Potamogetonion association.
description
The stem of the flat-stemmed spawning herb is up to 2 m long and is usually sparse in running waters, but often heavily branched in stagnant waters. What is particularly characteristic about it is that it is compressed and often appears winged. The leaves are all submerged, green or brownish in color and can be up to 20 cm long and 4 cm wide. At the bottom, these often have thickened glands. They also have five parallel leaf veins , three of which are clearly main veins. In between there are quite a lot of cross-nerved fiber bundles that form a very difficult to see central stripe network. An important characteristic is the mostly rounded tip of the blade, which rarely has a small tip. The small, reduced, usually 10 to 15 individual flowers are in a maximum 2 cm long spike, the stem is 3 to 12 cm long. The approximately 4 mm small fruits have short beaks. The pondweed also forms fan-shaped winter buds ( turions ).
The chromosome number of the species is 2n = 26.
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 .
Individual evidence
- ↑ Rafaël Govaerts (Ed.): Potamogeton compressus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 14, 2016.
- ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Page 103. Stuttgart, Verlag Eugen Ulmer, 2001. ISBN 3-8001-3131-5
Web links
- Potamogeton compressus. In: FloraWeb.de.
- Flat-stemmed pondweed . 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 .
- Potamogeton compressus L., map for distribution in Switzerland In: Info Flora , the national data and information center for Swiss flora .
- Distribution in the Netherlands [1] (Dutch)
- Thomas Meyer: Data sheet with identification key and photos at Flora-de: Flora von Deutschland (old name of the website: Flowers in Swabia )