T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Myriophyllum aquaticum (Parrot's feather)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(unranked): Core eudicots
Order: Saxifragales
Family: Haloragidaceae
Genus: Myriophyllum
Species: M. aquaticum
Binomial name: Myriophyllum aquaticum
Common names: Parrot's feather, Watermilfoil

Myriophyllum aquaticum is a flowering perennial vascular dicot plant and is native to the Amazon River in South America, but it can now be found on every continent except Antarctica. Myriophyllum aquaticum typically grows in freshwater streams, ponds, lakes, rivers, and canals that have a high nutrient content.
Myriophyllum aquaticum common name 'Parrot's feather gets its name from its feather-like leaves that are arranged around the stem in whorls of four to six.
The emergent stems and leaves are the most distinctive trait of parrot feather, as they can grow up to a 30 cm above the water surface and look almost like small fir trees. The leaves are a waxy gray-green and are deeply cut into many narrow lobes. The woody emergent stems grow over 150 cm long and will extend to the bank and shore.

Myriophyllum aquaticum is planted in indoor and outdoor aquatic gardens. It spreads easily and has escaped and has now become an invasive species throughout the world. While Myriophyllum aquaticum may provide cover for some aquatic organisms, it can seriously change the physical and chemical characteristics of lakes and streams. The Myriophyllum aquatic grows abundantly, shades out naturally-occurring algae, and clogs irrigation ducts and canals. It typically exist in bundles and extend out of the water. In large numbers, the plants make a dense mat on the water's surface. Because of this, they shade the water from sunlight and cause native plants to die because of light deficiency. The organisms that feed on the native plants can die off due to starvation. The dense mats also cause problems for recreation. Swimmers and boat propellers can become entangled and they are also a breeding ground for mosquitoes.

This plant is listed on New Zealand's National Pest Plant Accord.

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