Description

Plants 40–150 cm. Stems erect to spreading, green when young, fastigiately branched, glabrous, resinous. Leaves usually ascending or spreading; blades filiform to narrowly oblanceolate (terete or flattened, adaxially sulcate to concave), 12–55 × 0.5–3 mm, midnerves evident, usually not raised, apices acute to acuminate, faces glabrous or sparsely hairy, gland-dotted (in circular, deep pits), resinous; axillary fascicles of 2–15 leaves, shorter than subtending leaves. Heads usually borne singly. Peduncles 20–70 mm (mostly ebracteate). Involucres hemispheric, 8–14 × 8–18 mm. Phyllaries 24–32 in 2–3 series, green to tan, ovate to lanceolate, 4–10 × 0.5–3 mm, subequal, outer sometimes wholly herbaceous, usually mostly chartaceous, sometimes with green, medial stripes, midnerves conspicuous, raised, 1–2 collateral nerves often present, (margins membranous, minutely lacerate to fimbriate) apices acute to acuminate, abaxial faces usually glabrous, sometimes sparsely hairy, often stipitate-glandular, resinous. Ray florets 3–18; laminae elliptic to lanceolate, 7–15 × 2–5 mm. Disc florets 16–60; corollas 6–10 mm. Cypselae tan to brown, narrowly oblanceoloid, somewhat flattened, 4–5 mm (2-ribbed), sericeous to villous; pappi silvery, 5.8–7 mm. 2n = 18.