Page author: David Giblin
Carduus acanthoides
plumeless thistle, spiny plumeless thistle

Distribution: Occurring east of the Cascades crest in northeastern Washington; British Columbia to Washington, also in California, east to the northern Rocky Mountains, Great Plains, and eastern North America.

Habitat: Roadsides, fields, ditches, and other disturbed, open areas.

Flowers: July-October

Origin: Introduced from Europe

Growth Duration: Biennial

Conservation Status: Not of concern

Pollination: Bees, flies, beetles, wasps


Biennial herb 3-15 dm. tall, the stem tough and strongly spiny.


Leaves deeply lobed to pinnatifid, up to 25 cm. long and 8 cm. wide, the midrib beneath covered with long, soft hairs.


Heads clustered or solitary at the ends of the branches, erect, the disk mostly 1.5-2.5 cm. wide; involucre bracts narrow, under 2 mm. wide, erect, the middle and outer bracts spine-tipped, the inner softer and scarcely spiny; flowers purple; pappus capillary, not plumose.


Achenes glabrous.

Accepted Name:
Carduus acanthoides L.
Publication: Sp. Pl. 2: 821. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Carduus acanthoides in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Carduus acanthoides checklist entry.

OregonFlora: Carduus acanthoides information.

E-Flora BC: Carduus acanthoides atlas page.

CalPhotos: Carduus acanthoides photos.

USDA Plants: Carduus acanthoides information.

27 photographs:
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