Eurasian water milfoil
Alert
Be on the lookout for Eurasian water milfoil and report any sightings immediately.
Reporting options
- Report online.
- Phone Biosecurity Queensland on 13 25 23.
- Phone the Exotic Plant Pest Hotline on 1800 084 881.
Eurasian water milfoil stem
© David Bygott Creative Commons
Eurasian water milfoil submerged
© R Desbarats Creative Commons
Eurasian water milfoil submerged
© US Fish & Wildlife Service Creative Commons
Eurasian water milfoil out of water
© R Desbarats Creative Commons
Eurasian water milfoil infestation
© Robert L Johnson Creative Commons
Native to Eurasia and northern Africa, Eurasian water milfoil is a submerged invasive aquatic plant that can grow quickly and invade waterways. It has not been found in Queensland so far but could become a major pest here if introduced. It is a prohibited invasive plant under the Biosecurity Act 2014.
Scientific name
Similar species
- Native Myriophyllum ssp., Ceratophyllum demersum
Description
- It is a submersed aquatic plant.
- Emergent flower heads are orange to red.
- Leaves are dissected, 'feathery', in whorls of 4, and contain 12–21 leaflets.
- Long stems form surface-reaching mats.
- Plants form turions (dormant, detached buds) for overwintering.
- Rhizomes root to 10m depth, can grow 3–5m to surface.
3D model
View the 3D model to help you identify this plant. You can magnify the image and manipulate the view to inspect the plant from every angle.
Habitat
- Prefers slow-flowing and standing water bodies.
- Can grow in fresh and saline water.
- Grows well in nutrient-rich water.
Distribution
- Not known to occur in Queensland.
Life cycle
- Begins growth in spring with increasing water temperature. Achieves maximum growth in water temperatures above 18°C.
- Flowers in summer once stems reach water surface. Is pollinated by wind and insects.
- Plants fragment after flowering and die back to rhizomes towards winter. Rhizomes resprout in spring.
Impacts
Environmental
- Grows quickly in calm water bodies such as reservoirs and dams, eventually blocking waterways.
- Displaces native aquatic plants and reduces biodiversity.
- Can affect water quality when infestations are dense.
- Creates favourable mosquito habitat.
Social
- Impedes recreational activities such as waterskiing and fishing.
- Interferes with infrastructure such as irrigation.
- Poses danger for swimmers, who can become entangled.
How it is spread
- The plant propagates through seeds and stem fragments.
- Seeds can be spread by waterbirds.
- Fragments are spread by water currents and humans—this is the main way the plant spreads.
Prevention
Control
- Before undertaking any preventative or control actions, contact us online, by phone or in person.
Herbicide control
- Controlled with herbicides overseas (2,4D, Diquat, endothall, copper, fluridone).
Biological control
- No known biological control agents.
Legal requirements
- Eurasian water milfoil is a prohibited invasive plant under the Biosecurity Act 2014.
- You must not:
- keep it
- move it
- give it away
- sell it
- release it into the environment.
- You must not take any action that is reasonably likely to exacerbate the biosecurity threat posed by Eurasian water milfoil.
- You must take any action that is reasonably likely to minimise the biosecurity threat posed by Eurasian water milfoil.
- You must report any sightings immediately using 1 of these methods:
- Report online.
- Phone Biosecurity Queensland on 13 25 23.
- Phone the Exotic Plant Pest Hotline on 1800 084 881.
If you do any of these, penalties may apply.
Further information
- Contact us online, by phone or in person.
- View the Eurasian water milfoil 3D model.