|Botanical Name||Myriophyllum aquaticum|
IdentificationParrot's feather is an aquatic perennial herb which is bottom-rooted with stems emerging above the water surface. Leaves are finely divided having a feather like appearance. Flowers are minute without petals. Only female flowering plants are known in New Zealand.
HabitatsShallow freshwater drains, swamps, ponds, lake margins and slow moving water ways.
Impact to Biota and EcosystemsParrot's feather forms dense mats impedes water flow, increasing siltation and flood risk.
Dispersal Routes, Vectors, Infestation SourcesParts of floating mats or stem fragments with nodes, broken from the main body of the weed mass by wave motion, water level change or mechanical interference, move freely in water currents and once lodged on muddy streambanks away from the source, establish new colonies. Cultivation and drain clearing machinery also spread plant fragments to new sites. Parrot's feather is not known to set seed in New Zealand.
Control of Parrot's feather is extremely difficult. Mechanical harvesting with scoops or draglines gives only temporary relief and is not recommended; stem fragments floating in the stream or moved by harvesting equipment also spread the weed.
Physical control is not recommended, however plant material should be dried out before burial.
Good control has been achieved with a spray mix of 2% Glyphosate plus an Organosilicone penetrant. 200 ml Glyphosate plus 20 ml Oganosilicone/10 L water, sprayed when emergent growth reaches 50 mm high. Complete coverage is essential. Once established parrot's feather is very difficult to eradicate. Trials have been undertaken with Triclopy amine, but is not yet registed for use in New Zealand to control aquatic plants. A consent maybe required from your Regional council to spray a herbicide over water.
This plant is prohibited from propagation, sale and distribution within New Zealand!