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Bachelorís Button, Bluebottle, Cornflower, Garden Cornflower - Centaurea cyanus


Family: Asteraceae Ė Aster family Genus Common Name: Knapweed Native Status: Introduced
Centaurea cyanus - Bachelorís Button, Bluebottle, Cornflower, Garden Cornflower. This introduced species was brought over to North America as an ornamental by immigrants from Europe, and is commonly cultivated. It is now found wild in every state except Alaska, and is also found in most of Canada. It is considered weedy or invasive by some authorities.

In its native southern Europe, this flower grows among the grainfield, giving it the "Cornflower" common name.

Found in:
AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY

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Distribution of Centaurea cyanus in the United States and Canada:
USDA Plants Distribution Map temporarily unavailable.
Blue=Native; Grey=Introduced

Map from USDA Plants Database:
USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 21 Dec 2014). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

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Site: Boise Foothills, Ada County, ID Date: 2010-June-19Photographer: Gerald C. Williamson
Nikon D60
Tamron SP 90MM f/2.8 AF Macro
Centaurea cyanus is a member of the Asteraceae family with only disk flowers. The outer disk flowers are enlarge and somewhat bell-shaped, with sharp-pointed lobes. more frequently blue
Centaurea cyanus

Site: Boise Foothills, Ada County, ID Date: 2010-June-19Photographer: Gerald C Williamson
Nikon D60
The blossoms of Bachelor's Button are more commonly blue than other colors.
Click on the photo for a larger image
Centaurea cyanus

Site: Pioneer Cemetery, Horshoe Bend, ID Date: 2010-June-17Photographer: Gerald C Williamson
Nikon D60
While blue is the most common color, this photo shows some of the wide variety of colors of this flower.
Click on the photo for a larger image
Centaurea cyanus

Site: Pioneer Cemetery, Horshoe Bend, ID Date: 2010-June-17Photographer: Gerald C Williamson
Nikon D60
The inner florets vary in color as well.
Click on the photo for a larger image
Centaurea cyanus

Site: Pioneer Cemetery, Horshoe Bend, ID Date: 2010-June-17Photographer: Gerald C Williamson
Nikon D60
The inner florets vary in color as well.
Click on the photo for a larger image
Centaurea cyanus

Site: Boise Foothills, Ada County, ID Date: 2010-June-19Photographer: Gerald C Williamson
Nikon D60
Bachelor's Buttons can turn an entire field blue. Here highlighted by white Bachelor's Buttons and other white wildflowers.
Click on the photo for a larger image
Centaurea cyanus

Site: Pioneer Cemetery, Horshoe Bend, ID Date: 2010-June-17Photographer: Gerald C Williamson
Nikon D60
Click on the photo for a larger image
Centaurea cyanus

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All content except USDA Plants Database map Copyright Gerald C. Williamson 2014
Photographs Copyrighted by the named photographer