Common sulphur flower

Herbs, spreading mats, 1-3.5 × 2-6 dm. Aerial flowering stems erect, 1-2.5(-3) dm, tomentose to floccose, without one or more leaflike bracts ca. midlength. Leaves in loose rosettes; blade usually elliptic to ovate, 1-2.5(-3) × 0.5-1.5(-1.8) cm, white- to gray-lanate abaxially, less so to floccose or glabrous and green adaxially, margins plane. Inflorescences umbellate; branches 0.3-2.5(-8) cm, without a whorl of bracts about midlength; involucral tubes 2-3 mm, lobes 1.5-3 mm. Flowers 4-7(-8) mm; perianth bright yellow. 2n = 80.

Flowering Jun-Sep. Sandy to gravelly flats and slopes, mixed grassland and sagebrush communities, scrub oak and montane conifer woodlands; (1000-)1200-2700(-3100) m; Colo., Idaho, Mont., Utah, Wyo.

Variety umbellatum is widespread and rather common. Overlying a portion of the range of var. umbellatum is the glabrous-leaved var. aureum, but the latter occurs over a greater area and mainly much farther to the west. Still, clear distinction between the two is not always possible. Variety umbellatum is found in cultivation, especially in European gardens.