Thick-stemmed water hyacinth

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Thick-stemmed water hyacinth
Thick-stemmed water hyacinth (Eichhornia crassipes)

Thick-stemmed water hyacinth ( Eichhornia crassipes )

Systematics
Monocots
Commelinids
Order : Commelina-like (Commelinales)
Family : Water hyacinth family (Pontederiaceae)
Genre : Water hyacinths ( Eichhornia )
Type : Thick-stemmed water hyacinth
Scientific name
Eichhornia crassipes
( Mart. ) Solms

The thick-stalked water hyacinth ( Eichhornia crassipes ) is a perennial and free-swimming water plant from the family of the water hyacinth family (Pontederiaceae). It is one of the monocot plants , which can be recognized by the parallel-veined leaves. The water hyacinth originates from tropical South America and, like the closely related azure water hyacinth ( Eichhornia azurea ), is known in Europe as an ornamental plant, especially for garden ponds. Outside of South America, it is a neophyte that grows in water around the worldand is mostly rated as a fast growing weed .

distribution

The thick-stemmed water hyacinth was introduced as an ornamental plant from Brazil to North America in 1888 , where it is mainly found in Florida and California today . Four years later she was brought to Java and from there to other Southeast Asian islands . Then, within just a few years, she was also abducted to Australia , Japan , India and Africa .

Harmfulness and control

Example of invasive occurrence in Madagascar: lake overgrown with water hyacinths.
Fishermen have to collect the hyacinths that have immigrated for a number of years so that the lake does not become overgrown.

Without predators, the floating plant reproduces en masse and overgrows all inland waterways in Africa: a water hyacinth blanket doubles its area in just two weeks. Due to the lack of light, the aquatic plants under Eichhornia crassipes die and the fish also die as a result. In addition, the thick carpets of floating plants hinder shipping and fishing. Crocodiles find protection in plants and become a danger to humans. In addition, the plants remove oxygen from the water, as a result of which the acidity of the water increases and the flow rate decreases in rivers. This leads to the build-up of sludge.

As countermeasures, machines are being used in Nigeria to destroy the floating plant carpets. In other areas, herbicides were used that killed all other species and caused even greater damage. In Sudan were first weevil ( Neochetina eichhorniae and N. bruchi ) exposed that eat only water hyacinths. In Benin , the use of these beetles will save around 260 million dollars in the coming years, because according to initial information the project is proceeding satisfactorily. Possible negative side effects of the beetles are currently not known.

The thick-stemmed water hyacinth was added to the “List of Unwanted Species” for the European Union in 2016.

Use

Nevertheless, there are also positive aspects of a (controlled) planting of water hyacinth: these plants have the useful property of the water in which they live by it contains toxins to clean ( phytoremediation , Eng .: phytoremediation ). There are efforts to use this plant in Bangladesh to purify drinking water from arsenic : According to the WHO , 77 million Bangladeshis are at risk of arsenic poisoning there in 2005 , as contamination of the drinking water with 300 to 400 ppb arsenic is the norm there. It has been shown experimentally that thick-stemmed water hyacinths effectively remove arsenic from drinking water. The fibers are only suitable for the production of paper to a limited extent. They are also used to make wicker furniture when dried. As a mostly free-swimming plant, the species is also used as an aquarium plant.

literature

  • Mir Misbahuddin and Atm Fariduddin: Water hyacinth removes arsenic from arsenic-contaminated drinking water. In: Archives of Environmental Health. Vol. 57, pp 516-518, 2002 ISSN  0003 to 9896 (for phytoremediation ).
  • Christel Kasselmann : aquarium plants. Ulmer Verlag, Stuttgart 1995; 2nd, revised and expanded edition 1999, ISBN 3-8001-7454-5 , p. 280.

See also

Individual evidence

  1. ↑ List of Invasive Alien Species of Union Concern (PDF) accessed on July 15, 2016
  2. ↑ Phytotechnologies. United Nations Environment Program website .
  3. ^ WJ Nolad and DW Kirmse: The Papermaking Properties of Waterhyacinth. In: Journal of Aquatic Plant Management (JAPM). Vol. 12 (May 1974), pp. 90-97 ( PDF ).

Web links

Commons : Thick-Stalked Water Hyacinth  - Album with pictures, videos and audio files