Also known as: Parrot feather, parrot’s feather, parrotfeather water milfoil, water-feather
Parrotfeather’s vibrant leaves make it an appealing addition to any backyard pond or water feature, but it can drastically alter natural aquatic ecosystems. Once parrotfeather has escaped cultivation, it forms dense mats that shade out native aquatic plants and inhibit water flow and recreation.
|Life Cycle:||Perennial (life cycle lasts more than one year)|
|Early Detection and Rapid Response species:||Yes|
|Height:||Stems can grow 15 feet long (5 meters)|
|Leaf Description:||Feather-like leaves are arranged in whorlsWhorls An arrangement of leaves that radiate from a single point and wrap around the plant’s stem.. Above water leaves are bright green and resemble small fir trees. Submerged leaves are darker green.|
|Fruit & Flower Description:||Tiny, white flowers can be found on above water stems on female plants. |
It can reproduce by seed and stem fragments. Parrotfeather has male and female plants – both of which are needed to create viable seeds. Only female plants are present in Washington County.
|Bloom Time:||May to July|
- Parrotfeather grows in freshwater ponds, streams, and lakes.
- It thrives in areas with slow moving or still water that are protected from frost.
- Above water stems are well adapted to changes in water level. It’s stems can survive on the banks rivers and lakes.
- Parrotfeather forms dense mats that block sunlight from native aquatic species, leading to a monocultures.
- When the dense mats die back, their decompositionDecomposition The process of organic matter breaking down into smaller parts. reduce oxygen levels in water and create “dead zones” in the water.
- Heavy infestations can clog waterways, slowing streams, and impeding boat traffic.
What we’re doing about it:
- Parrotfeather is a priority species for the Tualatin SWCD. As such, our Invasive Species Program has been actively monitoring and treating it throughout the watershed.
- If identified within Washington County, a specially trained crew can come out survey for parrotfeather. If found, the crew will treat the infestation for free.
What you can do about it:
- If you think you’ve found parrotfeather anywhere in Oregon, please report it to the Oregon Invasive Species Hotline.
- Prevention is the best control for parrotfeather. Never dump aquariums near streams, rivers, or lakes. Most aquariums have plants and animals that can quickly spread and harm natural environments.
- It can be difficult to control once it has established in natural waterways. It is best to wait until the water level has dropped, usually mid-summer, before attempting to remove by hand or rake. All plant material should be thrown away in a plastic bag in the trash—not your yard waste bin or home compost.
Hornwort (Ceratophyllum demersum), a native aquatic perennial, is found in the same habitats as parrotfeather. Its light green and feathery appearance make it easy to mistake for parrotfeather. Hornwort’s leaves are forked, not feathery like parrotfeather’s.
Parrotfeather looks like another invasive aquatic species, spiked watermilfoil (Myriophyllum spicatum). These plants are difficult to tell apart, and often require a DNA test to separate. Both should be reported to the Oregon Invasive Species Hotline.
Noxious Weed Listing:
Download the Parrotfeather Best Management Practices Factsheet
- University of California, Weed Research & Information Center: Parrotfeather