How to identify Eurasion Milfoil

  • The plant is a perennial that grows under the water surface.
  • Feather-like green leaves circle the stem in groups of four or five.
  • Leaves have 12 or more thread-like segments.
  • Tiny, reddish flowers grow on spikes five to 20 centimetres long that rise above the water.
  • The plant blooms in late July and early August.

Eurasian water-milfoil looks similar to two other aquatic plants. The native northern water-milfoil (Myriophyllum sibiricum) has leaves with 11 or fewer leaf segments. The invasive parrotfeather (Myriophyllum aquaticum) has not been found in the wild in Ontario, but it is common in the aquarium trade. It has leaves that rise above the surface of the water, while only the terminal flower spike of Eurasian water-milfoil emerges from the water.