Rayless Tansyaster

Subshrubs, 3–35 cm (tufted or densely cespitose, often mound-forming); caudices much branched, taproot 2–20+ cm. Stems 10–30+, simple or branched in distal ¹ / 3 , moderately stout to stout, not wiry, hairy or minutely stipitate-glandular. Leaves: basal often persistent; cauline evenly spaced, blades oblong, obovate, lanceolate to spatulate or narrowly ovate to obovate, 7–60 × 2–13 mm, gradually reduced distally, margins usually evenly coarsely serrate to serrulate, teeth 4–16 per side, each tipped with white bristle 0.5–4 mm, faces sparsely to densely hairy (hairs subappressed), often minutely stipitate-glandular. Heads 1–10+. Peduncles sparsely to densely hairy, often stipitate-glandular; sometimes bracteate. Involucres hemispheric to campanulate, 0.5–1 × 0.6–1.5 cm. Phyllaries in 3–5 series, oblong to broadly lanceolate, 2–9 mm, apices obtuse to acute, tipped by white seta, faces usually densely stipitate-glandular. Ray florets 0. Disc florets 15–50+; corollas 5–8.5 mm. Cypselae oblong to narrowly obovoid, 2–3.5 mm, ribs 12–24, densely whitish to tawny hairy; pappi whitish to tawny, 3–7 mm, a few abaxial bristles to ¹ / 3 of longest.

Eriocarpum grindelioides Nuttall, Trans. Amer. Philos. Soc., n. s. 7: 321. 1840; Haplopappus nuttallii Torrey & A. Gray; Machaeranthera grindelioides (Nuttall) Shinners