Montana County Noxious Weed List

Friday, June 22, 2001
Headlines

This article was Archived on Monday, July 01, 2002

*New Additions Effective February 11, 2000 Category 1. Category 1 noxious weeds are weeds that are currently established and generally widespread in many counties of the state. Management criteria includes awareness and education, containment and suppression of existing infestations and prevention of new infestations. These weeds are capable of rapid spread and render land unfit or greatly limit beneficial uses.

• Canada Thistle (Cirsium arvense)
• Field Bindweed (Convolvulus arvensis)
• Whitetop or Hoary Cress (Cardaria draba)
• Leafy Spurge (Euphorbia esula)
• Russian Knapweed (Centaurea repens)
• Spotted Knapweed (Centaurea maculosa)
• Diffuse Knapweed (Centaurea diffusa)
• Dalmatian Toadflax (Linaria dalmatica)
• St. Johnswort (Hypericum perforatum)
• Sulfur (Erect) Cinquefoil (Potentilla recta)
• Common tansy (Tanacetum vulgare)*
• Ox-eye Daisy (Chrysanthemum leucanthemum L.)*
• Houndstongue (Cynoglossum officinale L.)*

Category 2. Category 2 noxious weeds have recently been introduced into the state or are spreading from their current infestation sites. These weeds are capable of rapid spread and invasion of lands, rendering lands unfit for beneficial uses. Management criteria includes awareness and education, monitoring and containment of known infestations and eradication where possible.

• Dyers Woad (Isatis tinctoria)
• Purple Loosestrife or Lythrum (Lythrum salicaria, L. virgatum, and any hybrid crosses thereof).
• Tansy Ragwort (Senecio jacobea L.)
• Meadow Hawkweed Complex (Hieracium pratense, H. floribundum, H. piloselloides)
• Orange Hawkweed (Hieracium aurantiacum L.)
• Tall Buttercup (Ranunculus acris L.)*
• Tamarisk [Saltcedar] (Tamarix spp.)*

Category 3. Category 3 noxious weeds have not been detected in the state or may be found only in small, scattered, localized infestations. Management criteria includes awareness and education, early detection and immediate action to eradicate infestations. These weeds are known pests in nearby states and are capable of rapid spread and render land unfit for beneficial uses.

• Yellow Starthistle (Centaurea solstitialis)
• Common Crupina (Crupina vulgaris)
• Rush Skeletonweed (Chondrilla juncea)