Plants 50–400 cm. Stems erect, much branched, twigs crowded, green when young, becoming reddish brown to gray, glabrous or sparsely hairy, usually covered with resin-filled pits. Leaves (moderately crowded) ascending to spreading; blades linear to narrowly oblanceolate (terete, sulcate, or flattened), 5–50 × 0.5–2 mm, midnerves obscure or evident abaxially, apices acute, faces glabrous or moderately hairy, gland-dotted (in circular, deep pits), resinous; axillary fascicles with 1–10 leaves, shorter than subtending leaves. Heads in racemiform to thyrsiform arrays (to 50 × 2–15 cm). Peduncles 2–15 mm (bracts 5–10+, leaflike). Involucres turbinate to subcampanulate, 4–7 × 2.5–4 mm. Phyllaries 16–24 in 3–5 series, mostly tan, narrowly oblong to elliptic, 1.5–6 × 0.4–0.8 mm, unequal, mostly chartaceous, midnerves evident on at least distal 1 / 2 , slightly to strongly thickened, expanded distally, (margins narrowly membranous, sometimes ciliate distally) apices acute to rounded, abaxial faces glabrous, outer sometimes gland-dotted (sessile), frequently resinous. Ray florets 2–8; laminae 4–5 × 1–1.8 mm. Disc florets 6–20; corollas 5–7 mm. Cypselae tan to brown, subcylindric, 3.5–4 mm, moderately to densely hairy; pappi off-white to brown, 5–8 mm. 2n = 18.
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