Parrotfeather milfoil (Myriophyllum aquaticum) is an aquatic invasive species. This species can be found in slow flowing freshwater bodies including ponds and canals. It grows best in areas with high light conditions and nutrient dense environments. Parrotfeather milfoil leaves look like spikes and are stiff and feathery. They grow in groups of 4 to 6. The stems often emerge at least 1 foot above the water and there will be small white flowers present. Although the flowers are difficult to see from a distance. The part of the plant submerged may have a reddish tint. This species spreads when a small piece of a female plant enters a new body of water. It is important to check your boat before transporting it between lakes or waterways.
Have you seen this species? Please report it to us or on the MISIN website or smartphone app! Please includes pictures for ID verification.
Environmental effects
As with many invasive species, parrotfeather milfoil can out compete native plants and reduce diversity. Dense mats commonly form where the species is present. This can decrease the amount of sunlight below the surface of the water. Mosquitos often use the mats for breeding as well. Boats may have trouble traveling through dense mats as well.
Treatments
There is no single treatment that works to easily get rid of parrotfeather milfoil. Two options are laid out below, but research is ongoing to find a biological control.
NON-CHEMICAL CONTROL METHOD
- Hand pulling: this method will offer temporary control of parrotfeather milfoil. This method should not be used on areas greater than an acre. It is best to pull this species between April and October.
CHEMICAL CONTROL METHOD
- Herbicide application: the emergent stems are waxy, so it is hard for herbicide to penetrate the surface and kill the plant. The herbicide may even weigh the stem down and cause the treatment to be washed away before drying. Before applying herbicide to an aquatic environment, make sure you have the proper permits to do so.