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Montana Field Guide

Montana Field Guides

Spiny Plumeless-thistle - Carduus acanthoides
Other Names:  Plumeless Thistle, Welted Thistle

Non-native Species

Global Rank: GNR
State Rank: SNA

Agency Status
MNPS Threat Rank:
C-value: 0

External Links

General Description
Stems 30–150 cm. Herbage sparsely villous on midveins. Leaves: basal wing-petiolate; blades oblanceolate, deeply pinnately lobed, 10–20 cm long; cauline sessile, reduced upward. Inflorescence with several erect heads on spiny stems; peduncles 1–2 cm long. Involucres 14–20 mm high; phyllaries linear-lanceolate, appressed, the outer spine-tipped, inner purple, long-attenuate. Disk corollas 12–20 mm long. Achenes 2–3 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Species Range

Range Comments
Introduced to northern U.S. (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 317

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)



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Citation for data on this website:
Spiny Plumeless-thistle — Carduus acanthoides.  Montana Field Guide.  .  Retrieved on , from