Annuals or biennials, 25–150(–200+) cm. Leaves on proximal 2/3–3/4 of each stem; blades of undivided cauline leaves oblong, ovate, or elliptic, margins entire or denticulate, midribs sometimes sparsely pilose. Heads in (± pyramidal) paniculiform arrays. Involucres (8–)10–12+ mm. Phyllaries usually reflexed in fruit. Florets 10–15(–25+); corollas bluish or whitish, seldom deliquescent. Cypselae: bodies brown (often mottled), ± compressed-lanceoloid to -fusiform, 4–5 mm, beaks ± stout, 0.1–0.5(–1) mm, faces 5–6-nerved; pappi white, 4–5 mm. 2n = 34.
"Robust, leafy-stemmed annual or biennial 5–20 dm; lvs mostly petiolate and not sagittate at the base, often hairy along the main veins beneath, otherwise glabrous or nearly so, the blade 8–30 × 2.5–20 cm, from elliptic (or cordate) and merely toothed to evidently pinnatifid; heads numerous in an ample, paniculiform infl, with 11–17(–27) blue (white) fls; invol 9–14 mm in fr; achenes 4–6 mm, narrowed upward, beakless or with a stout beak sometimes a third as long as the body, several-nerved on each face, tending to be thickened on the margins; pappus white; 2n=34. Thickets, woods, and moist, open places; N.Y. to Fla., w. to Minn., Kans., and Tex. June–Sept. (L. villosa, the form with merely toothed lvs)"