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Viper's Bugloss


Echium vulgare - Boraginaceae Family - Biennial

Other common name: Blueweed

viper's_bugloss_1_tile   viper's_bugloss_2_tile  viper's_bugloss_3_tile  viper's_bugloss_4_tile   


  • Flowers: Abundant flowers are funnel-shaped and bright blue to purple in color. Flowers also have external hairs.
  • Seeds:  Seeds are 0.8-0.12 in. (2-3 mm) long, brownish grey in color, have a rough texture, and an elongated triangular shape. Seeds can remain viable for several years in the soil.
  • Leaves: Leaves are oblanceolate and have white 'speckles' that give them a dimpled appearance. They can also have relatively long white hairs.
  • Flowering Time: Flowering occurs June to August, seeds maturing about a month after bloom.
  • Life cycle:  Viper’s Bugloss is a biennial that spends its first year as a small, flowerless rosette. In the late summer of its second year, the plant produces flowers, with seeds following a month later. The plant then dies off the following winter.  


  • Viper’s Bugloss has been known to act as a secondary host for multiple floral diseases and can spread them throughout an area. 
  • It contains pyrrolizidine alkaloids that can prove fatal to cattle if ingested in large quantities.
  • Viper’s Bugloss is primarily seed spread and can easily travel long distances by hitchhiking on vehicles and clothing. 


Most effective control methods


  • Small infestations of Viper’s Bugloss can be effectively controlled by manually pulling and disposing in the trash.
  • There are currently no biological control agents approved for use against Viper’s Bugloss in the US.
  • Chemical control can be effective against Viper’s Bugloss if applied prior to flowering and seed production.

Large Images

Rob Routledge, Sault College,

Viper's bugloss: flowers



Rob Routledge, Sault College,

Viper's bugloss: stems and foliage



Ansel Oommen,

Viper's bugloss: flowers



Robert Vidéki, Doronicum Kft.,

Viper's bugloss



Robert Vidéki, Doronicum Kft.,

Viper's bugloss: infestation




Viper's bugloss: seed



K. Fenner, DPIPWE

Viper's bugloss: seedlings



Rob Routledge, Sault College,

Viper's bugloss


  • Viper's Bugloss Fact Sheet

  • References

    Alberta Invasive Species Council. (2014, January). Blueweed [PDF file]. Retrieved from View PDF

    DiTomaso, J.M., G.B. Kyser et al. (2013). Weed Control in Natural Areas in the Western United States [PDF file]. Weed Research and Information Center, University of California. Retrieved from View PDF

    Graves, M., Mangold, J., & Jacobs, J. (2010, March). Biology, ecology, and management of blueweed [PDF file]. Retrieved from View PDF

    Prather, T., Miller, T., & Hulting, A. (2016, June). Control of problem weeds. Retrieved from

    Texas (2012, May 4). Echium Vulgare. Retrieved from

    Washington State Noxious Weed Control Board. Blueweed. Retrieved from

    Wyoming Pest Detection Program. Viper’s bugloss or blueweed (Echium vulgare L.) [PDF file]. Retrieved from View PDF