Alternanthera philoxeroidesPerennial herb - grows in water or land.
Ceratophyllum demersumCan grow to more than 10m deep.
Zizania latifoliaA dense, mat-forming grass.
Egeria densa, Lagarosiphon majorBlock waterways and pumps.
Myriophyllum aquaticumA blue-green sprawling perennial plant.
Glyceria maximaAlso known as swamp grass.
Identify, control and prevent these weeds from spreading.
A guide to help slow the spread of freshwater pests.