Marsh goldenweed

Haplopappus uniflorus (Hooker) Torrey & A. Gray subsp. linearis D. D. Keck, Aliso 4: 103. 1958

Plants 5–20 cm. Stems 1–4, ascending, reddish, slender, lightly tomentose, glabrescent, eglandular. Leaves: basal sessile to winged-petiolate, blades linear (grasslike), 40–120 × 2–5 mm, margins usually entire, rarely with a few small teeth; cauline sessile, blades linear, 10–20 × 1–3 mm; faces sericeous to sparsely shaggy-tomentose, eglandular. Heads usually borne singly, terminal. Peduncles 4–8 cm. Involucres hemispheric, 7–10 × 13–18 mm (bases white-tomentose). Phyllaries in 2 series, loosely appressed, linear to linear-lanceolate, 8–9 mm, equal, bases chartaceous, margins entire, ciliate, apices green, acute, faces sparsely villous. Ray florets 25–50; corollas 6–10 mm. Disc florets 30–60; corollas 5–7 mm. Cypselae subcylindric, 2–4 mm, faces sericeous; pappi tawny, 3–4 mm.

Flowering Jun–Jul. Marshy grassy areas, vernal stream banks, swales, meadows; 1600–2500 m; Idaho, Nev., Oreg.

Pyrrocoma linearis is easily distinguished by its linear, entire, grasslike leaves, and terminal, single heads. This species is similar to P. uniflora and was formerly included there as a subspecies. Pyrrocoma uniflora differs in having lanceolate or oblanceolate leaves with dentate margins.