Boundary Invasive Species Society
Eurasian watermilfoil
(Myriophyllum spicatum)
Identification:
Impacts:
It is an aggressive competitor. It reduces the diversity of native plants. It starts growing earlier in the season so it reaches the surface sooner than other plants creating a dense canopy. The mass makes swimming dangerous and restricts boating and fishing opportunities. The plants clog water intakes and foul beaches.
Management:
Preventing introduction into other water bodies is very important so Please Clean Drain Dry all recreation equipment especially boats. Never dump aquariums into natural areas. Please report it if you see this plant in waterbodies other than Christina Lake.
Eurasian watermilfoil is in Christina Lake, Christina Creek and Idabel Lake. Please report it if you find this plant elsewhere in the Boundary
This is a fresh water plant although it can tolerate somewhat salty water. It is a submerged perennial with reddish flowering stems breaking the surface later in the season. It has pink flowers and it blooms between Late July and early August. It has green feather-like leaves and the stem is brownish-red to green. It has a 4 leaved whorl and each leaf has 12-21 leaflet pairs. The number of leaflet pair is a good distinguishing character to separate it from the native watermilfoils which generally have less than 12 leaflet pairs. There is some hybridizing between native and invasives so DNA analysis is being used in many areas.
A piece of plant the size of a postage stamp can start a new infestation and fragmentation is the main method of spread. It can easily hitch a ride on boats.
The Regional District of Kootenay Boundary operates a Eurasian watermilfoil control program in Christina Lake using divers. For information on this program please visit their website.