Page authors: Don Knoke, David Giblin
Rhaponticum repens
hardheads, Russian knapweed, Turkestan thistle
WTU specimens
Other herbaria

Distribution: Introduced chiefly east of the Cascades in Washington; widely distributed throughout much of North America.

Habitat: Dry, open areas at low elevation and foothills.

Flowers: June-September

Origin: Introduced

Conservation Status: Not of concern


Coarse, bushy perennial from deep rhizomes, 4-8 dm. tall, finely loose white-woolly throughout.


Lower cauline leaves up to 15 cm. long by 4 cm. wide, often few lobed; other leaves numerous, smaller, entire or with a few teeth.


Heads numerous, terminating the branches; involucre pale yellow-green, 9-15 mm. high, the middle and outer bracts broad, glabrous, with rounded hyaline tips, the inner bracts narrower and tapering, with hairy tips; flowers purple; pappus bristles 11 mm. long; receptacle densely bristly.



Accepted Name:
Rhaponticum repens (L.) Hidalgo

Synonyms & Misapplications:
Acroptilon repens (L.) DC. [FNA19]
Centaurea repens L. [HC]
Additional Resources:

PNW Herbaria: Specimen records of Rhaponticum repens in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Rhaponticum repens checklist entry.

E-Flora BC: Rhaponticum repens atlas page.

CalPhotos: Rhaponticum repens photos.

USDA Plants: Rhaponticum repens information.

26 photographs:
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