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 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
The following animal species have been reported as pollinators of this species or genera where their geographic ranges overlap: Bombus vagans
, Bombus bifarius
, Bombus fervidus
, and Bombus terricola
(Thorp et al. 1983, Colla and Dumesh 2010).