Trans. Amer. Philos. Soc., n. s. 7: 350. 1840.
Plants (15–) 20–40 (–65) cm. Basal leaves: blades ± silvery to white or gray-green, rounded-deltate or deltate to triangular-deltate, 5–25 × 3–15 cm, bases ± cordate, margins entire, apices acute to attenuate, faces sericeous, tomentose, tomentulose, or velutinous (at least abaxially, usually glanddotted as well), sometimes glabrescent. Heads usually borne singly, sometimes 2–3+. Involucres hemispheric to turbinate, 12–25 mm diam. Outer phyllaries lanceolate to oblanceolate or linear, (15–) 20–25 (–30+) mm, equaling or surpassing inner, apices acute to acuminate. Ray laminae 20–40 mm. 2n = 38.
Phenology: Flowering (Apr–)May–Jun(–Jul).
Habitat: Openings, banks, flats, meadows, ridges, sagebrush scrub, conifer forests
Elevation: (100–)900–2500(–3000) m
Alta., B.C., Ariz., Calif., Colo., Idaho, Mont., Nev., Oreg., S.Dak., Utah, Wash., Wyo.
Balsamorhiza sagittata grows east of the Cascade-Sierra axis to the Rocky Mountains and Black Hills. It is one of the more spectacular of all spring-flowering plants in the northwestern United States. Hybrids occur along lines of contact between B. sagittata and almost all species of sect. Balsamorhiza except B. macrophylla (a high polyploid).
"broader" is not a number.