Eichhornia crassipes
Water Hyacinth ( Eichhornia crassipes )
The Water Hyacinth ( Eichhornia crassipes ) is a perennial and free-floating aquatic plant of the family of water hyacinth plants ( Pontederiaceae ). It belongs to the monocotyledons, which is good to recognize the parallel veined leaves. The water hyacinth is native to tropical South America and is, as something rare and the closely related Azure water hyacinth ( Eichhornia azurea ), in Europe as an ornamental plant especially for garden ponds known. Outside of South America it is a world in the aquatic growing neophyte and is usually rated as fast-growing weeds.
Dissemination
The Water Hyacinth was introduced in 1888 as an ornamental plant from Brazil to North America, where it occurs today, especially in Florida and California. Four years later she was brought to other South East Asian islands to Java and from there. Then she was dragged in just a few years after Australia, Japan, India and Africa.
Harmfulness and control
Without predators, the floating plant increased massively overgrown and all inland waters in Africa: A water hyacinth ceiling doubled its area in just two weeks. Due to the lack of light water plants die under Eichhornia crassipes and the fish die as a result. In addition, the thick carpets of floating plants to impede navigation and fishing. Crocodiles found in the crop protection and become a danger to people. In addition, the plants remove oxygen from the water, as a result increases the acidity of the water in rivers and decreases the flow rate. This results in the deposition of sludge.
As countermeasures machines are used in Nigeria, which will destroy the floating plants rugs. In other areas, herbicides were used, which destroyed also all other species and inflicting an even greater harm. In Sudan, weevils were ( Neochetina eichhorniae and N. bruchi ) exposed to only eat water hyacinth for the first time. In Benin, is through the use of these beetles about 260 million dollars will be saved in the coming years because, according to initial information, the project is satisfactory. Possible negative side effects of the beetles are not currently known.
Benefit
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, to be cleansed of toxins contained therein ( " phytoremediation ", English:. Phytoremediation ). Thus, there are efforts to use this plant in Bangladesh to purify drinking water by arsenic: according to the WHO, 77 million Bangladeshis are at risk of arsenic poisoning, since contamination of drinking water with 300 to 400 ppb arsenic are the rule there there in 2005. It was shown experimentally that Hyacinth Water Hyacinth effectively remove arsenic from drinking water. The fibers are only limited to the production of paper. Also wicker furniture are dried out of them manufactured.
System
Other Eichhornia species: