Invasive Species Council of British Columbia
Invasive Plant

Eurasian watermilfoil

Myriophyllum spicatum

About This Species

Eurasian watermilfoil (Spiked watermilfoil) is an aquatic plant which has been let loose from aquariums from its native range in Europe. It prefers still or slow-moving water with silty or sandy bottoms. It spreads by roots, seeds, buds, and stem fragments. Eurasian watermilfoil can quickly take over waterways, causing sluggish water that attracts mosquitos and reduces the recreational potential of the waterway such as swimming and boating. Eurasian watermilfoil is designated as a Management Species by the BC Provincial Priority Invasive Species List. 

How to Identify

Eurasian watermilfoil is an aquatic plant with long, slender reddish-brown stems. 

Flowers are small, red or yellow, and stick out from the water 5-10 cm. Fruits are small capsules. 

Its leaves are very thin, feathery and green-black. They grow in numerous small leaflets in whorls of four off the stem. 


Take Action

Prevention is the best approach.

Don't Let it Loose

Don't Let It Loose

Learn about best practices

Invasive species are plants, animals or other organisms that are not native to BC, and have serious impacts on our environment, economy and society. Never release your plants and animals into the wild or dump aquariums or water garden debris into rivers, streams, lakes or storm sewers!

Clean, Drain, Dry

Learn about best practices

The Clean Drain Dry program empowers you to help reduce the spread of invasive plants and organisms to BC waters by following the clean, drain, dry procedure on all watercraft and equipment.


Use the app

Observe and report to protect BC’s biodiversity

Report through this website

Use our form to tell us what you’re seeing and where.



Click or drag files to this area to upload. You can upload up to 3 files.
Please include photos of the suspected species to help potential identification by experts.
Please be specific and give us an address if possible.