Priority 1B weeds have limited presence in Montana. Management criteria will require eradication or containment, where present, and prevention and education elsewhere.
 

Noxious Weed Species Common Name	Scientific Name
Blueweed	Echium vulgare
Japanese Knotweed Complex	Polygonum cuspidatum
Rush Skeletonweed	Chondrilla juncea
Scotch Broom	Cytisus scoparius
Purple Loosestrife	lythrum salicaria