Page author: Don Knoke
Centaurea nigra
hardheads, black knapweed, lesser knapweed
WTU specimens
Other herbaria

Distribution: Introduced in the Pacific Northwest and northeastern United States

Habitat: Uncommon weed in disturbed soil

Flowers: July - October

Origin: Introduced from Europe

Conservation Status: Not of concern


Perennial 1-12 dm. high, covered throughout with fine, short hairs.


Leaves toothed to shallowly lobed to entire, the basal petiolate, lance-ovate to elliptic, the cauline reduced upwards and becoming sessile.


Heads terminating the rather numerous branches; involucre 12-18 mm. high, and a little broader than high; the middle and outer involucral bracts tipped with comb-like teeth that are black, and 2-3 times as long as they are wide; pappus 1 mm. long; receptacle densely bristly.

Accepted Name:
Centaurea nigra L.
Publication: Sp. Pl. 2: 911. 1753. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Centaurea nigra in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Centaurea nigra checklist entry.

E-Flora BC: Centaurea nigra atlas page.

CalPhotos: Centaurea nigra photos.

USDA Plants: Centaurea nigra information.

1 photographs:
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