Annuals, 100(–200+) cm. Stems erect, glabrous or glabrate (glaucous). Leaves mostly cauline; mostly opposite; petioles 0.5–1.2 cm; blades (often 3-nerved distal to bases) lanceolate, 6–11 × 0.7–1.9 cm, bases cuneate, margins ± serrate, faces scabrous, not gland-dotted . Heads 1–15. Peduncles 2–8 cm. Involucres hemispheric, 10–15 mm diam. Phyllaries 15–25, lanceolate, 8–9 × 1.5–2 mm, (margins ciliate) apices acuminate, abaxial faces glabrate. Paleae 5–7, subentire to ± 3-toothed (apices purplish, glabrous). Ray florets ca. 12; laminae 12–25 mm. Disc florets 50+; corollas 3.5–4 mm, lobes reddish purple; anthers dark, appendages dark. Cypselae 2.5–3.2 mm, glabrous (± tuberculate); pappi of 2 aristate scales 1.5–2 mm. 2n = 34.
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