Common Sowthistle - Sonchus oleraceus
Smooth Sow Thistle, Hare's Colwort, Swinies, Annual Sowthistle
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 et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
From Eurasia but widespread across nearly all of North America.
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans
, Bombus bifarius
, Bombus fervidus
, and Bombus terricola
(Thorp et al. 1983, Colla and Dumesh 2010).
- Literature Cited AboveLegend: View Online Publication
- Colla, S.R. and S. Dumesh. 2010. The bumble bees of southern Ontario: notes on natural history and distribution. Journal of the Entomological Society of Ontario 141:39-68.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Thorp, R.W., D.S. Horning, and L.L. Dunning. 1983. Bumble bees and cuckoo bumble bees of California (Hymenoptera: Apidae). Bulletin of the California Insect Survey 23:1-79.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
- Simanonok, M. 2018. Plant-pollinator network assembly after wildfire. Ph.D. Dissertation. Bozeman, MT: Montana State University. 123 p.
- Simanonok, M.P. and L.A. Burkle. 2019. Nesting success of wood-cavity-nesting bees declines with increasing time since wildfire. Ecology and Evolution 9:12436-12445.