Rydberg’s goldenbush

Macronema obovatum Rydberg, Bull. Torrey Bot. Club 27: 618. 1900; Haplopappus rydbergii S. F. Blake; H. watsonii A. Gray var. rydbergii (S. F. Blake) S. L. Welsh

Plants 20–40 cm. Stems erect to ascending, green, becoming tan, branched, stipitate-glandular. Leaves ascending; blades obovate to spatulate (flat), 10–30 × 4–12 mm, midnerves evident (1–2 collateral nerves sometimes present, abaxial reticulum of secondary veins often evident), (margins often undulate) apices obtuse, apiculate, faces densely stipitate-glandular; axillary fascicules usually absent. Heads in cymiform to racemiform arrays (1–3 cm wide). Peduncles 1–7 mm (stipitate-glandular). Involucres obconic, 6–8 × 4–7 mm. Phyllaries 22–28 in 4–6 series, tan, ovate to elliptic, 1–6 × 0.5–1.2 mm, strongly unequal, mostly chartaceous, midnerves evident, (margins narrowly membranous, entire or minutely lacerate) apices acute to acuminate, abaxial faces mostly stipitate-glandular, resinous. Ray florets 4–9; laminae elliptic, 3.5–6 × 1.2–1.8 mm. Disc florets 9–15; corollas 6.2–6.8 mm. Cypselae tan to reddish brown, columnar, 3.5–4.5 mm [ribs unknown], villous; pappi tan, 4–5.5 mm. 2n = 36.

Flowering late summer–fall. Open rocky soils, mostly associated with desert shrub, pinyon-juniper, and lower ponderosa pine; 1500–3400 m; Utah.