What is Variable-Leaf (or two-leaf) Water Milfoil?

Variable Leaf Water Milfoil (Myriophyllum heterophyllum) is a submerged aquatic invasive plant that looks like some native species including native milfoils. The plant’s feathery leaves are arranged in dense whorls, usually four to six leaves per whorl. Each feathery leaf has seven to 14 pairs of thread-like leaflets. The dense leaf whorls make the plants look like bottle brushes.

A water plant

Stems are thick and reddish. A second leaf type, which is blade-like and serrated, appears in mid to late summer when the plant forms an erect spike. Tiny white flowers and the blade-like leaves are whorled around the spike that emerges from the water. The plant sprouts new growth from turions, roots, overwintering plants and plant fragments. The plant breaks into pieces easily and is often transported from lake to lake on boat trailers or fishing gear. Dense mats can grow from plant fragments degrading habitat and reducing recreational access.

How do we stop it?

Clean, Drain, and Dry: Always clean, drain, and dry your boat, paddle gear, and footwear after use. This prevents the transfer of organisms between water bodies.

  • Clean all plant stems and fragments and mud from boats and trailers before leaving your lake or river and dispose of them in an aquatic invasive species disposal station if one is available.
  • Empty all water from your gear well before moving to a new body of water.
  • Dispose of leftover bait in the trash, not in the water.
  • Clean out waders and wading boots before moving to a new body of water.
  • Dry your boat and gear thoroughly between water bodies by towel drying or drying in the sun for at least 5 days.

Read more about Clean, Drain, and Dry requirements and best practices at the following websites:

NYS DEC
Northern Forest Canoe Trail
Lake Champlain Basin Program

If You See It, Report It

You can report Brazilian Elodea sightings through the iMapInvasives website, the iMapInvasives mobile app, or by contacting the Adirondack Park Invasive Plant Program (APIPP).

Volunteer with ADK

You can help ADK survey ponds and lakes for aquatic invasive species such as Yellow Floating Heart, European frog-bit, European Water Chestnut, and Curly Leaf Pond Weed. For more information on the Backcountry Water Monitors Project and upcoming workshops and outings, please visit our website.

 

Learn More About Variable-Leaf Water Milfoil (sources for description above)

https://www.adkwatershed.org/stewardship/invasive-species-info/variable-leaf-milfoil

http://www.mainevlmp.org/mciap/herbarium/VariableWatermilfoil.php

http://www.adkinvasives.com/Invasive-Species/Detail/41

Please also see all invasive species of concern for the Adirondack Park: http://adkinvasives.com/species_of_concern/