Phytologia 50: 358. 1982.
Plants 10–30 (–40) cm. Basal leaves: blades silvery, lanceolate or lanceovate, 9–30 × 2–7 cm (1-pinnatifid, lobes oblong to oblanceolate, 5–35 × 3–17 mm), bases cuneate, ultimate margins usually entire (plane or weakly revolute, obscurely, if at all, ciliate), apices rounded to acute, faces densely sericeous. Heads borne singly. Involucres campanulate to hemispheric, 11–20+ mm diam. Outer phyllaries broadly ovate to triangular-ovate, 12–20 mm, slightly surpassing inner, apices acuminate to attenuate (margins not ciliate). Ray laminae 15–20 mm (adaxially puberulous on veins).
Phenology: Flowering Apr–May.
Habitat: Serpentine outcrops, among surface rocks, in crevices, hillsides, dry streamsides among cobbles
Elevation: 400–1800 m
Balsamorhiza sericea hybridizes with B. deltoidea.
"broader" is not a number.