Long-leaved pondweed

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Long-leaved pondweed
Long-leaved pondweed (Potamogeton praelongus)

Long-leaved pondweed ( Potamogeton praelongus )

Systematics
Class : Bedecktsamer (Magnoliopsida)
Monocots
Order : Frog-spoon-like (Alismatales)
Family : Pondweed family (Potamogetonaceae)
Genre : Spawn herbs ( Potamogeton )
Type : Long-leaved pondweed
Scientific name
Potamogeton praelongus
Wulfen

The long-leaved pondweed ( Potamogeton praelongus ) is a species of aquatic plant from the family of the pondweed plants (Potamogetonaceae).

description

The long-leaved pondweed is a perennial, herbaceous plant and reaches a length of up to 0.8 to 3 meters, the stem is oval to round in cross section. The sessile leaves lie under water and are arranged in a spiral. They are narrowly ovate-lanceolate, round at the base and sheathed around the stem, the edge is smooth and entire, the tip of the leaf rounded to blunt. Floating leaves are missing. The middle rib stands out clearly, the side ribs are finely meshed with one another. The 3 to 8.1 centimeters long, fibrous stipules are linear-lanceolate, whitish to green, permanent and laterally rolled up.

Flowering time is June to July, the inflorescence is an unbranched spike standing above the water surface , it is cylindrical and 3.4 to 7.5 centimeters long. The long-leaved pondweed is wind pollinating and the flowers are petalless . To protect the reproductive organs, however, greenish appendages that resemble a four-petal corolla develop on the connective of the anthers . The inflorescence axes are axillary or terminal and reach a length of 9.5 to 53 centimeters.

The fruits are sessile nuts (aggregate stone fruit). They are green-brown, inverted ovoid, always facing away from the axis and occasionally keeled to the side, 4 to 5.7 millimeters long and 3.2 to 4 millimeters wide.

The number of chromosomes is 2n = 52.

distribution

Spike inflorescence of the long-leaved pondweed

The long-leaved pondweed is widespread, it is found in the temperate zones of Eurasia as well as in North America (Greenland to Mexico) from the coast to 3000 meters above sea level in deep, pH-neutral to alkaline lakes and rivers. It is a character species of the Potamogetonetum filiformis from the association Potamogetonion, but also occurs in societies of the association Ranunculion fluitantis. It thrives in 50-300 centimeters of water depth.

In the Allgäu Alps, it rises in the Vorarlberg part in Kalbelesee on the Hochtannbergpass up to 1660 meters above sea level.

In many European countries their populations have declined sharply (Great Britain by 25%, France by 30%, Germany by 60%, the Czech Republic by 90%). The main reasons for the increasing disappearance of the species are the increasing eutrophication of the waters.

literature

  • Erich Götz: Identify plants with the computer. 2001, ISBN 382528168X
  • Robert R. Haynes, C. Barre Hellquist: Potamogetonaceae. In: Flora of North America , Vol. 22, ( Online ), accessed November 17, 2008

Individual evidence

Most of the information in this article has been taken from the sources given under literature; the following sources are also cited:

  1. ↑ Urania Plant Kingdom , Higher Plants, Vol. 2 . Urania-Verlag Leipzig, Jena, Berlin, 1976, p. 336 .
  2. ↑ Information on the long-leaved pondweed at ufz.de ( Memento of the original from August 9, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Accessed October 17, 2010 @1@ 2Template: Webachiv / IABot / www.ufz.de
  3. ↑ 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.  105 .
  4. ↑ Rafaël Govaerts (ed.): Potamogeton praelongus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Accessed June 1, 2020.
  5. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , pp. 130-131.
  6. ↑ Information on the long-leaved pondweed at FloraWeb.de , accessed on November 17, 2008

Web links

Commons : Potamogeton praelongus  - album with pictures, videos and audio files