Aquatic Weeds

Day 5 – Aquatic Weeds

Did you know…? Montana’s state weed list also includes aquatic invasive plant species! Some plants are submerged, while others are not. The state list has eight (8) aquatic invasive plant species listed:

  • Priority 1B: Purple loosestrife
  • Priority 2A: Yellowflag iris, Eurasian watermilfoil, Flowering rush
  • Priority 2B: Curlyleaf Pondweed
  • Regulatory (3): Hydrilla, Brazilian waterweed, Parrot feather watermilfoil


For Day 5 of MNWAW, we will learn about three of the eight species: Eurasian watermilfoil, Curlyleaf pondweed, Yellowflag iris. Use these resources to learn something new and/or as a way to promote and distribute information to your constituents, family, friends, and neighbors.

Fact Sheets
Eurasian Watermilfoil—MSU Extension
Curlyleaf Pondweed—MSU Extension
Yellowflag Iris—MSU Extension


Eurasian Watermilfoil—Lower Hudson PRISM
Eurasian Watermilfoil—University of Idaho
Curlyleaf Pondweed—MT Department of Agriculture
Curlyleaf Pondweed—University of Idaho
Yellowflag Iris—MT Department of Agriculture
Yellowflag Iris—University of Idaho
Eurasian Watermilfoil from a hot spring—Explore Biodiversity; Rob Nelson


Activities & Helpful Websites
Help Protect Montana from Aquatic Invasive Species activity book—Montana FWP
Aquatic Invasive Species Singalong—Invasive Species Action Network


Other Articles & Information
AIS Species Identification Guide—Montana FWP
Protect Montana Waters from Aquatic Invasive Species—Montana FWP
Eurasian Watermilfoil—Montana Outdoors


As MNWAW is declared statewide, help us create a united front in the fight against noxious weeds in Montana, educate those around us, and celebrate the wins. Don’t forget to watch our gun raffle fundraiser LIVE on our Facebook page at 5pm.

Follow along, share, and engage with us!!




Becky Kington
MWCA Executive Director
PO Box 708
Twin Bridges, MT 59754

MWCA Business Members

Upcoming Events

Upcoming Events

The 2025 MWCA Scenic Calendar is in production. This year’s theme includes Early Detection, Rapid Response invasives and new technologies in weed management. We’ve tried to enlarge the calendar grids as much as we can for better usability. There have been many awesome shots submitted by our members and voting is nearing completion. Calendars should be ready for distribution around August 1. If you would like to order calendars, they are $3 each in bulk orders of 10 or more and $5 for single orders. Please contact Becky if you would like to order some of these fabulous calendars.