- Water feather
- Parrot’s feather
- Brazilian watermilfoil
General: Parrotfeather is an aquatic plant in the Watermilfoil family (Haloragaceae).
Flowers: Inconspicuous (1.6 mm) white flowers that emerge from the axils of shoots.
Stems: Reddish submersed stems creep along the water surface, while green emergent stems grow vertically up to 30 cm above the water. Stems can grow 2 – 5 m long, with extensive branching throughout.
Leaves: Feather-like leaves are heterophyllous, meaning they exist both above and below water. Emergent leaves have whorls of 4 – 6 leaves per node and appear bright green, waxy and stiff. Submerged leaves have whorls of 3 – 6 leaves per node and are tinged red.
Roots: Parrotfeather has thin, hair-like roots that arise from the nodes of stems.
Fruits: Parrotfeather does not produce seed outside its native range.
- Cutleaf Watermilfoil (Myriophyllum pinnatum) has darker stems and foliage than Parrotfeather. It is native to Eastern North America. (We were unable to source an image for this species.)
- Eurasian Watermilfoil (Myriophyllum spicatum) also resembles Parrotfeather, but it is reddish-brown and has more pairs of leaflets per leaf (14 – 21).
Habitat and Origin
Parrotfeather is native to South America and arrived in Canada as an ornamental pond plant.
Parrotfeather’s habitat is limited to non-tidal, freshwater, slow-moving water bodies including tributaries, ponds, lakes and canals. This plant thrives in ample light, alkaline and high-nutrient environments.
While Parrotfeather can withstand mild winters, temperatures in the Sea to Sky Corridor typically reach below tolerable conditions for it to persist year-round, though it’s likely that climate change will be broadening its range.
Propagation & Vectors of Spread
In BC, Parrotfeather reproduces vegetatively through plant fragments. As male plants are not present outside their native range, female plants cannot produce seeds.
While Parrotfeather does spread vegetatively, humans are a primary means of dispersal. Parrotfeather is commonly purchased for aquaria and aquatic gardens, and can travel long distances by hitching a ride on boats, trailers, and other gear.
Ecological, Economic, & Health Impacts
- Can form dense mats that outcompete native aquatic plants, especially in shallow ponds.
- Impedes water flow and traps sediment.
- Creates suitable habitat for mosquito larvae.
- Dense infestations can impede the movement of boats, damage equipment, and clog drainage ditches.
What Can I Do?
Parrotfeather is not yet found in communities of the Sea to Sky region, so PREVENTION of spread is key:
Learn to identify Parrotweed: use the images presented in this profile page to learn how to identify Parrotweed.
What to do if you spot it: You can report any Parrotweed sighting by clicking here.
- Clean, Drain, and Dry all watercraft. Rinse all mud, debris, and plant fragments from all equipment, wading gear, and boats.
- Ensure all plant parts are bagged and covered during transport to a designated disposal site.
- Plant Parrotfeather in an aquarium or a water garden, no matter how well-contained its enclosure may seem.
- Dispose of aquarium plants into water bodies.
- DO NOT compost!
- Attempting to control Parrofeather by mechanical means tends to spread the plants and should only be conducted with extreme caution, ideally in small, contained water bodies.
- For larger water bodies, we advise the use of a cloth screen or floating net to contain the treatment area.
- Raking or hand-pulling may offer temporary control; however, this approach is very labour intensive, as dense mats are heavy and can damage equipment.
- The benthic barrier method can effectively smother plants: by using an opaque mat, one can block the sunlight and oxygen that are necessary for the plant to survive. However, note that this treatment may impact other species as well.
- Alternatively, re-planting riparian areas with non-invasive species can create shade and reduce Parrotfeather’s growth.
- For best results, combine several mechanical control methods and monitor treated sites often.
Chemical control is impossible due to the aquatic nature of this plant.
There is no biocontrol available for this plant.
BioNET-EAFRINET, Myriophyllum aquaticum (Parrot’s feather) Factsheet, https://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Myriophyllum_aquaticum_(Parrots_Feather).htm
California Invasive Plant Council, Myriophyllum aquaticum, https://www.cal-ipc.org/plants/profile/myriophyllum-aquaticum-profile/
Centre for Invasive Species and Ecsystem Health, Parrot-Feather, https://www.invasive.org/alien/pubs/midatlantic/myaq.htm
Electronic Atlas of the Flora of BC, Myriophyllum aquaticum, https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Myriophyllum+aquaticum
Electronic Atlas of the Flora of BC, Myriophyllum pinnatum, https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Myriophyllum+pinnatum
Electronic Atlas of the Flora of BC, Myriphyllum spicatum, https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Myriophyllum+spicatum
Great Lakes Aquatic Nonindigenous Species Information System, Myriophyllum aquaticum (Vell.) Verdc., https://nas.er.usgs.gov/queries/GreatLakes/FactSheet.aspx?Species_ID=235
Invasive Plant Atlas of the United States, Parrotfeather, https://www.invasiveplantatlas.org/subject.html?sub=3054
United States Geological Survey, Myriophyllum aquaticum (Vell.) Verdc., https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=235