Narrow Leaf Ironweed

Plants (2–)5–6+ dm. Stems glabrous or glabrate. Leaves mostly cauline; blades filiform, 5–9+ cm × 1–3+ mm, l/w = 25–50+, abaxially glabrate (pitted, awl-shaped hairs in pits), adaxially puberulent, glabrescent (sometimes pitted). Heads in corymbi-form arrays. Peduncles 6–20+ mm. Involucres narrowly campanulate, 7–9(–10+) × 4–5+ mm. Phyllaries 30–40+ in 5–6+ series, sparsely tomentose, glabrescent, margins arachno-ciliolate, the outer lanceolate to subulate, 1–3 mm, inner oblong to lanceolate, 5–7+ mm, tips acute. Florets 10–12+. Cypselae 3–4 mm; pappi fuscous to purplish, outer scales 25+, 0.1–0.5 mm, contrasting with 35+, 6–7+ mm inner bristles. 2n = 34.