Perennials monocarpic, 40–150 cm; taprooted. Stems usually 1, erect, less commonly several, ascending, simple to sparingly short-branched in distal 1/2, less commonly openly branched, villous with jointed trichomes; branches on distal stems 0–many, short, ascending. Leaves: blades linear to oblong or elliptic, 10–30+ × 1–10 cm, margins flat to undulate, subentire to coarsely dentate or shallowly to deeply pinnatifid, lobes lance-oblong to broadly triangular, spinulose to spiny-dentate or shallowly lobed, main spines 3–12 mm, abaxial faces green and subglabrous to gray-or white-tomentose with felted arachnoid trichomes, ± villous to tomentose along major veins with septate trichomes, rarely glabrous or glabrate, adaxial ± green, glabrous or villous with septate trichomes; basal often present at flowering, spiny winged-petiolate or sessile; principal cauline well distributed, proximally winged-petiolate, distally sessile, gradually reduced, bases sometimes short-decurrent (0–2 cm); distal ± reduced, often narrower than the proximal, sometimes with non-pigmented bases. Heads several–many, erect, usually in racemiform or spiciform arrays, usually closely subtended by clustered ± leafy bracts. Peduncles 0–15+ cm. Involucres (green), broadly ovoid, 1.5–2.5 × 1.5–2.5 cm, loosely villous with septate trichomes, sparingly if at all arachnoid. Phyllaries in 4–8 series, subequal, ± lanceolate, bases appressed, apices ascending, linear to broadly expanded, erose to lacerate or spiny-fringed, spines straight, slender, 2–3 mm, abaxial faces with or without narrow glutinous ridge; apices of inner flexuous, sometimes expanded and erose. Corollas white, ochroleucous, 19–23 mm, tubes 6.5–8.5 mm, throats 7.5–11 mm, lobes 4–5 mm; style tips 4–5.5 mm, conspicuously exserted. Cypselae brown, 5.5–6.5 mm, apical collars not differentiated; pappi 17–20 mm. 2n = 34.
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