Working together to strengthen and support noxious weed management efforts in Montana.

Weed ID

The most important component in addressing noxious weeds is education; you need to know the  weeds we are dealing with in Montana. Weeds are most easily identified by their flower color, but sometimes you have to look at other features including their leaf structure. There are many ways to classify leaf structure; we have used leaf edges or margins.  All but two of the weeds on the Montana Noxious Weed list can be classified into three edges: smooth, toothed and lobed.

 Below, we have provided you with a simple guide to help you determine if your weed is one of the weeds listed on the Montana Noxious Weed list.  If you click on any of the weeds or the menu below,  you will see additional information about the weed including: more plant photos in various growth stages, a detailed description including key features, the scientific name and common names  for the plant, a map of counties where it has been discovered, information about treatment options, and commonly confused weeds. 

We have separated the weeds by aquatic (water) and terrestrial (land) plants to further help your identification.

Unfortunately, there is   no one silver bullet effective in getting rid of invaders. Managing and preventing weeds can require a variety of techniques.  This is called Integrated Weed Management (IWM).  If you wish to know more about IWM visit our weed control pages.

The Montana Weed Control Association mission addresses invasive noxious weeds in Montana.  There are many other invasive species coming into the state every day.  While we do not include any invasive species beyond plants on our website, we support efforts to protect the ecosystems in Montana from all invasive species.

Terrestrial Noxious Weeds

   Canada Thistle
   Common Tansy
   Houndstongue    Dyer's Woad
   Russian Knapweed    Leafy Spurge
   Spotted Knapweed    Meadow Hawkweed Complex
   Purple Loosestrife    Rush Skeletonweed
  Saltcedar    St. John's Wort
   Blueweed    Scotch Broom
   Diffuse Knapweed    Sulfur Cinquefoil
   Field Bindweed    Tall Buttercup
   Hoary Alyssum    Tansy Ragwort
   Knotweed Complex    Dalmatian Toadflax
   Oxeye Daisy    Yellow Toadflax
   Perennial Pepperweed    Yellow Starthistle
   Whitetop    Yellowflag Iris
       Orange Hawkweed

Aquatic Noxious Weeds

   Flowering Rush    Curlyleaf Pondweed
      Eurasian Water Milfoil

Regulated Plants

Regulated Plants are NOT Montana listed noxious weeds.  These regulated plants have the potential to have significant negative impacts.   The plant may not be intentionally spread or sold other than as a contaminant in agricultural products.   The state recommends research, education and prevention to minimize the spread of regulated plants.

   Cheatgrass    Russian Olive
   Hydrilla    

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