Herbs, perennial, erect, aromatic, coarse, 1-1.5 m tall, ca. 1.5 cm in diam. at base, much branched, branches densely tomentose. Stems conspicuously winged by decurrent leaves. Median leaves sessile, lanceolate to broadly lanceolate, 6-12 × 2.5-4 cm, thinly tomentose with viscid glands on surfaces, base attenuate, margin serrate, apex acuminate. Capitula 7-8 mm in diam. when fresh, to ca. 10 mm in diam. when dried, 4-5 mm, in compound terminal and axillary corymbs; peduncle 5-25 mm. Involucre hemispheric; phyllaries greenish brown, 4-or 5-seriate, outer ones widely elliptic to widely obovate, 1-2 × 1-1.5 mm, tomentose abaxially, margins ciliate, apex acuminate, inner lanceolate to linear-lanceolate, 3-4 × 0.4-0.6 mm, grading to glabrous. Receptacle flat, glabrous. Marginal florets numerous; corolla white, 3-3.5 mm, 3-lobed; achenes brown, cylindric, with 5 pale ribs, 0.6-0.8 × ca. 0.2 mm, with viscid glands; pappus white, slightly longer than corolla. Central florets 50-60; corolla white, purplish toward summit, 2.5-3 mm, sparingly glandular hairy at base; anthers acute at apex, shortly tailed at base; anthers and style exserted; achenes vestigial. Fl. and fr. Mar-Oct. 2n = 20.
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Perennials, 50–200 cm; fibrous-rooted. Stems minutely hirtellous to strigillose and sessile-glandular (winged by decurrent leaf bases). Leaves sessile; blades usually lanceolate to lance-elliptic (proximal sometimes spatulate or oblanceolate), mostly 5–15 × 1–3(–4) cm, margins shallowly and closely toothed, faces minutely hirtellous to strigillose and sessile-glandular. Heads in corymbiform arrays. Involucres hemispheric to cupulate, 4–7 × 8–10 mm. Phyllaries greenish to cream, ± stipitate-glandular (outer oval-oblong to linear-attenuate). Corollas white or rose-purple. Pappi persistent, bristles distinct. 2n = 20.
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