Proc. Acad. Nat. Sci. Philadelphia 4: 20. 1848.
Subshrubs or shrubs, 50–200 cm. Stems erect, virgately branched. Leaves cauline; alternate; petiolate or ± sessile; blades mostly pinnately lobed (lobes 3–7+, linear to filiform), distal (not lobed) linear to filiform, faces usually sericeous to strigillose, sometimes glabrate or glabrous, usually glanddotted. Heads disciform, in (ebracteate or nearly so) paniculiform arrays, or borne singly or in glomerules of 1–5+. Involucres ± hemispheric, 4–5+ mm diam. Phyllaries persistent, 10–15+ in 2–3 series, distinct, outer 5–7 herbaceous, inner scarious to membranous (± villous). Receptacles convex; paleae spatulate to cuneiform, membranous, distally ± villous. Pistillate florets 5; corollas 0. Functionally staminate florets 10–25+; corollas whitish, funnelform, lobes 5, erect (filaments connate, anthers distinct or weakly coherent). Cypselae plumply obovoid, obcompressed or weakly 3–4-angled, smooth, ± villous, little, if at all, glanddotted; pappi 0. x = 18.
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