Page authors: Don Knoke, David Giblin
Centaurea solstitialis
yellow starthistle, St. Barnaby's thistle
WTU specimens
Other herbaria

Distribution: Introduced in most of the United States; chiefly east of the Cascades in Washington and Oregon

Habitat: Noxious weed of dry, disturbed areas

Flowers: July - September

Origin: Introduced

Conservation Status: Not of concern


Annual or biennial, 2-8 dm. tall, thinly white-woolly throughout, the stem winged.


Basal leaves lyrate and pinnatifid, up to 20 cm. long and 5 cm. wide; cauline leaves smaller, becoming linear and entire upward.


Heads several, broader toward the base; involucre 10-15 mm. high, its middle and outer bracts spine-tipped, the larger spines 11-22 mm. long; flowers yellow; pappus of the outer flowers wanting, that of the others 3-5 mm. long; receptacle densely bristly.

Accepted Name:
Centaurea solstitialis L.
Publication: Sp. Pl. 2: 917. 1753. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

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

WA Flora Checklist: Centaurea solstitialis checklist entry.

E-Flora BC: Centaurea solstitialis atlas page.

CalPhotos: Centaurea solstitialis photos.

USDA Plants: Centaurea solstitialis information.

21 photographs:
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