9. Chrysothamnus viscidiflorus (Hooker) Nuttall, Trans. Amer. Philos. Soc., n. s. 7: 324. 1840.
Yellow or sticky-leaf rabbitbrush
Crinitaria viscidiflora Hooker, Fl. Bor.-Amer. 2: 24. 1834
Shrubs, 10–120 cm; with woody, branched caudices, bark whitish tan, becoming gray, flaky and fibrous with age. Stems ascending, green, soon becoming tan, glabrous or puberulent, sometimes resin-dotted, often resinous. Leaves ascending, spreading, or deflexed; sessile; blades with evident midnerves plus sometimes 1–2 pairs of smaller, collateral nerves, linear to lanceolate, 10–75 × 0.5–10 mm, flat or sulcate, often twisted, margins often undulate, sometimes ciliate, apices acute to apiculate, faces glabrous or puberulent. Heads in dense, rounded cymiform arrays (to 7 cm wide), not overtopped by distal leaves. Involucres cylindric to obconic or campanulate, 4–7 × 1.5–2.5 mm. Phyllaries 12–24 in 3–5 series, in spirals or weak vertical ranks, mostly tan, green to brown subapical patch often present, midnerves usually evident (at least distally), linear-oblong, lanceolate to elliptic or obovate to spatulate, 1–5 × 0.5–1.2 mm, unequal, chartaceous, margins scarious, eciliate or ciliolate to erose-ciliolate, flat or convex, sometimes weakly keeled, apices acute to obtuse or rounded, sometimes apiculate, flat, faces glabrous or puberulent. Disc florets (3–)4–5(–14); corollas 3.5–6.5 mm, lobes 0.7–1.7 mm; style branches 2.2–3.2 mm (exserted beyond spreading corolla lobes), appendages 0.8–1.5 mm (length shorter than stigmatic portion). Cypselae tan to reddish brown, turbinate, 2.5–4.2 mm, ± 5-angled, moderately to densely hairy; pappi tan, 3.5–6 mm.
Subspecies 5 (5 in the flora): w North America.