Lactuca virosa

Biennials, 20-120(-200+) cm. Leaves on proximal ¹/2-²/3 of each stem; blades of undivided cauline leaves obovate to spatulate, margins denticulate, midribs usually prickly-setose. Heads in paniculiform arrays. Involucres 12-15 mm. Phyllaries usually reflexed in fruit. Florets 10-15; corollas yellow, usually deliquescent. Cypselae: bodies purplish to blackish, ± flattened, ± elliptic, 3.5-4 mm, beaks ± filiform, 2.5-3.5 mm, faces 5-7-nerved; pappi white, 5-6 mm. 2n = 18.

Flowering May, Oct. Disturbed sites; 10-400 m; introduced; Ala., Calif., D.C.; Europe.