Blueweed

http://farm3.static.flickr.com/2350/2197246765_bc70c8138f.jpg
http://farm3.static.flickr.com/2350/2197246765_bc70c8138f.jpg

Scientific name: Echium vulgare
Common name(s): blueweed, blue thistle, blue devil, viper's bugloss, snake flower
Origin: Native.
http://weedsandwildflowers.info/images/Blueweed-DSC_2987.jpg
http://weedsandwildflowers.info/images/Blueweed-DSC_2987.jpg
Identification: Bright blue blossoms on the upper stems, gray nut like fruit in groups of four, rough hairy leaves, which are painful to tough, become smaller at the top of the plant as well as hairs on the stems that have dark swollen bases averaging in 0.3 - 0.8m tall.
Characteristics: Invasive, in places such as pastures, roadsides and sandy soils. This weed drops many seeds which may contaminate crop seeds, acting as a alternative to host diseases. The rough seeds which fall can stick to clothing, animal fur, and feathers and be carried a distance away.
Habitat: This weed grows in low to mid elevations of British Columbia in the central and south central areas of the province and is a major concern in the Kootenay, Okanagan, Thompson, and Cariboo region.
Control/ eradication recommendations: After working in infested fields new blueweed infestations can be prevented by planting certified crop seed and cleaning up equipment. Hoeing, grubbing, or hand pulling small patches may be effective if repeated for several years or intense cultivation is repeated through the growing season for a minimum two years. Certain herbicides such as Dicamba, 2,4-D, MCPA, and picloram have provided control but repeated applications may be necessary, and control may vary depending on the year.
References: http://www.weedsbc.ca/weed_desc/blueweed.html
http://www.agf.gov.bc.ca/cropprot/weedguid/blueweed.htm
http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/blueweed.htm