Viper's bugloss (or blueweed) identification and control
Viper's bugloss (a.k.a blueweed), a regulated Class B noxious weed, is a 1-3-foot-tall biennial that grows mostly in pastures and disturbed areas. Basal leaves are lance-shaped, growing smaller as they move up the plant's hairy stems. Blue flowers with 5 unequal petals grow in long, narrow clusters. This plant reproduces by seed.
This Class B noxious weed, also known as blueweed, has a limited distribution in Washington State. The major infestations in the state are found in eastern Washington, but it is occasionally found in King County on disturbed roadsides and construction areas as well as in ornamental gardens. Control is required in King County, Washington.
This species is also on the Washington quarantine list (known as the prohibited plants list) and it is prohibited to transport, buy, sell, offer for sale, or to distribute plants or plant parts, seeds in packets, blends or "wildflower mixes" of this species, into or within the state of Washington.
For more information on noxious weed regulations and definitions, see Noxious weed lists and laws.
A member of the borage family, the bright blue flowers of viper's bugloss form in
distinctive fiddleneck coils at the end of the flowering stems. Flowers are visible from June to August. This taprooted biennial is covered with stiff, bristly hairs and flecks of swollen purple blotches at the base of long stem hairs. Plants grow to about 32" tall and spread by seed.
This noxious weed is competitive in rangeland and in non-cropland areas. It is unpalatable and it crowds out beneficial forage plants.
Additional information on viper's bugloss
- Washington State Noxious Weed Control Board (external link)
Viper's bugloss photos
Report viper's bugloss in King County, Washington
- Please notify us through our online infestation form
Locate viper's bugloss in King County, Washington
- Use our interactive noxious weed map and search for viper's bugloss