Priority  1A:  These weeds are not present in Montana. Management criteria will require eradication if detedted; education; and prevention.

• Yellow starthistle (Centaurea solstitialis)

Priority  1B:  These weeds have limited presence in Montana.  Management criteria will require eradication or containment and education.

• Dyer's woad (Isatis tinctoria)
• Flowering rush (Butomus umbellatus)
• Japanese knotweed complex (Polygonum spp.)
• Purple loosestrife (Lythrum spp.)
• Rush skeletonwed (Chondrilla juncea)
• Eurasian watermilfoil (Myriophyllum spicatum)
• Scotch broom ( Cytisus scoparius)
• Curlyleaf pondweed (Potamogeton crispus)

Priority  2A:  These weeds are common in isolated areas in Montana.  Management criteria will require eradication or containment where less abundant.  Management shall be prioritized by local weed districts.

• Tansy ragwort (Senecio jacobaea) 
• Hoary Alyssum (Berteroa incana)
• Meadow hawkweed complex (Hieracium spp.)
• Orange hawkweed (Hieracium aurantiacum)
• Tall buttercup (Ranunculus acris)
• Perennial pepperweed (Lepidium latifolium)
• Yellowflag iris (Iris pseudacorus)
• Blueweed (Echium vulgare)

Priority  2B:  These weeds are abundant in Montana and widespread in many counties. Management criteria will require eradication or containment where less abundant.  Management shall be prioritized by local weed districts. 

• Canada thistle (Cirsium arvense)
• Field bindweed (Convolvulus arvensis)
• Common tansy (Tanacetum vulgare)
• Saltcedar (Tamarix spp.)
• Houndstongue (Cynoglossum officinale) 
• Leafy Spurge (Euphorbia esula)
• Oxeye Daisy (Leucanthemum vulgare)
• Russian Knapweed (Acroptilon repens)
• Spotted Knapweed (Centaurea stoebe)
• St. Johnswort (Hypericum perforatum)
• Sulfur Cinquefoil (Potentilla recta)
• Whitetop or Hoary Cress (Cardaria draba)
• Yellow Toadflax (Linaria vulgaris)

Priority  3:  Regulated Plants: (NOT MONTANA LISTED NOXIOUS WEEDS)Thses regulated plants have the potential to have significant negative impacts.  The plants may not be intentionally spread or sold other that as a contaminant in agricultural products.  The state recommends research, education and prevention to minimize the spread of the regulated plant.

• Cheatgrass (Bromus tectorum)
• Hydrilla (Hydrilla verticillata)
• Russian olive (Elaeagnus angustifolia)