Narrow-leaved waterweed
Narrow-leaved waterweed | ||||||||||||
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Narrow-leaved waterweed ( Elodea nuttallii ) |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Elodea nuttallii | ||||||||||||
( Planch. ) H.St.John |
The narrow-leaved waterweed ( Elodea nuttallii ), also (after the English botanist Thomas Nuttall, 1786-1859) called Nuttall's waterweed , is a water plant from the genus waterweed ( Elodea ). The species originates from North America and is considered a naturalized, spreading neophyte in Europe .
features
The submerged rungs are 30 to 100 centimeters long. The small, dark green leaves sit on the flooding stalks, usually in groups of three. They are one to three centimeters long, often rigid, narrow triangular to linear, curved back and twisted strongly spirally. They end with a long point, not rounded in the shape of a tongue. The length of the leaves is 3.5 to ten times their width of one to three millimeters. Compared to Elodea canadensis, the species has a more curled, uneven appearance and has narrower leaves. However, the Canadian waterweed can sometimes have slightly bent back leaves, which makes it difficult to distinguish.
The inconspicuous, three to five millimeters small, whitish-light purple flowers sit on long whitish stalks that protrude or rest on the surface of the water. Elodea nuttallii is dioecious, but in Central Europe there are almost only specimens with female flowers (flowering period: June to September). The reproduction is therefore also here purely vegetative . The species forms winter buds .
The number of chromosomes is 2n = 52.
Occurrence
The narrow-leaved waterweed is native to southern Canada to the United States. It occurs in Europe and Asia as a neophyte. In Switzerland it was added to the black list of invasive neophytes and subject to the release ordinance. Nuttall's waterweed has been observed in continental Europe since around 1939 (first occurrence in Belgium) and is still widespread. In 1961 an isolated occurrence with exclusively male specimens was discovered in the Vogtland.
In Central Europe it forms its own Elodea nuttallii society from the Potamogetonion association.
literature
- Martina Stengert, Petra Podraza, Klaus van de Weyer: The development of Elodea nuttallii (PLANCH.) ST. JOHN in the Ruhr reservoirs under the influence of floods in spring 2006 and summer 2007. German Society for Limnology (DGL). Extended summary of the 2007 annual conference (Münster), Werder 2008.
- Christel Kasselmann : aquarium plants. Ulmer Verlag, Stuttgart 1995; 2nd, revised and expanded edition 1999, ISBN 3-8001-7454-5 .
Web links
- Narrow-leaved waterweed. In: FloraWeb.de.
- Narrow-leaved waterweed . 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 .
- Elodea nuttallii (Planch.) H. St. John, map for distribution in Switzerland In: Info Flora , the national data and information center of the Swiss flora .
- Distribution in the Netherlands [2] (Dutch)
- Thomas Meyer: Data sheet with identification key and photos at Flora-de: Flora von Deutschland (old name of the website: Flowers in Swabia )
- Neoflora (BfN): Invasive, alien plants in Germany: E. nuttallii
Individual evidence
- ^ Tropicos. [1]
- ↑ Rafaël Govaerts (ed.): Elodea nuttallii. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved June 19, 2018.
- ^ Federal Office for the Environment FOEN: Invasive Alien Species . ( admin.ch [accessed on August 6, 2019]).
- ↑ S. Buholzer, M. Nobis, N. Schoenenberger, S. Rometsch: List of the alien invasive plants of Switzerland . Ed .: Infoflora. ( infoflora.ch [accessed on August 6, 2019]).
- ↑ Archived copy ( memento of the original from August 14, 2015 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.
- ↑ St. John, H. (1965): Monograph of the genus Elodea (Hydrocharitaceae): Part 4 and summary. The species of eastern and central North America. Rhodora 67: 1-35, 155-180
- ^ 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. 113 .