Bighead Knapweed (Centaurea macrocephala)

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Perennial with several un-branched stems. Grows to 50-170 cm in height. Leaves are light-green in color, leaf much longer (5-20 cm) than wide (2-10 cm), with widest point below middle, wavy/ toothed edges, hairy and pointed tips. Bracts are thin & papery, with fringed edges. Flower: is yellow color and approx. 6 cm across.

Key Identifiers
  • Bigheaded flower
  • Huge flower buds, covered with papery metallic brown scales, look somewhat like artichokes
Location in Canada
Flora of North America lists locations in only Ontario and Quebec for Canada. Ornamental plants are known to exist throughout Alberta. Possible escape is possible, and of concern, as bighead knapweed is identified as an invader.

Pacific Northwest Extension Publication - Identification of Knapweed and Starthistles in the Pacific Northwest

Similar species
Not aware of any confusing species.

Richard Old, XID Services, Inc.,

Richard Old, XID Services, Inc.,


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Yellow Starthistle (Centaurea solstitialis)
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For more information about the content of this document, contact Chris Neeser.
This document is maintained by Shelley Barkley.
This information published to the web on April 2, 2012.
Last Reviewed/Revised on February 26, 2018.