Acroptilon repens
hardheads, Russian knapweed, Turkestan thistle
Blooms: June-September
Habit: herb
Duration: perennial
Origin: Introduced
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.
Species Description:
General: Coarse, bushy perennial from deep rhizomes, 4-8 dm. tall, finely loose white-woolly throughout.
Leaves: 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.
Flowers: 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.
Fruits: Achene
Accepted Name:
Acroptilon repens (L.) DC.
Synonyms:
Centaurea repens L.
Treated in Flora of the PNW as:
Centaurea repens
Additional Resources:
PNW Herbaria Specimens: View list of
Acroptilon repens specimens in the Consortium of Pacific Northwest Herbaria database.
WTU Herbarium Specimens: View list of
Acroptilon repens specimens in the WTU Herbarium database.
Washington Flora Checklist:
Acroptilon repens treatment.
E-Flora BC:
Acroptilon repens atlas page.
CalPhotos:
Acroptilon repens images.
USDA Plants Database:
Acroptilon repens.
Additional photographs of Acroptilon repens:
(click on a thumbnail to view larger photo)

Richard Old

Richard Old

Richard Old

Richard Old

Sue Winterowd, 2003

Sue Winterowd, 2005

Sue Winterowd, 2005