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Montana Field Guide

Montana Field Guides

Common Sowthistle - Sonchus oleraceus
Other Names:  Smooth Sow Thistle, Hare's Colwort, Swinies, Annual Sowthistle

Non-native Species

Global Rank: GNR
State Rank: SNA

Agency Status
MNPS Threat Rank:
C-value: 0

External Links

General Description
Taprooted annual. Stems erect, 30–100 cm tall, mostly simple. Leaves lanceolate to oblanceolate, pinnately lobed to mostly entire, 5–25 cm long, winged-petiolate below, becoming sessile and auriculate above. Involucres 8–15 mm high; phyllaries glabrous or with patches of tomentum. Ray ligules 3–6 mm long, inconspicuous. Achenes brown, 2–4 mm long, bumpy between the ribs (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Species Range
Montana Range


Range Comments
From Eurasia but widespread across nearly all of North America.

Observations in Montana Natural Heritage Program Database
Number of Observations: 15

(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)

Disturbed soil of roadsides, fields, lawns; plains, valleys (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

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Citation for data on this website:
Common Sowthistle — Sonchus oleraceus.  Montana Field Guide.  .  Retrieved on , from