Emperor's sulphur flower

Herbs, spreading mats, 1-3.5 × 2-6 dm. Aerial flowering stems erect, 1.5-2.5 dm, thinly floccose or glabrous, without one or more leaflike bracts ca. midlength. Leaves in loose rosettes; blade broadly elliptic, 1.5-3(-4) × 1-1.5 cm, glabrous on both surfaces at full anthesis, margins plane. Inflorescences compound-umbellate, branched 2-4 times; branches thinly floccose or glabrous, without a whorl of bracts ca. midlength; involucral tubes 2-3.5 mm, lobes 1-2.5 mm. Flowers 4-7 mm; perianth bright yellow.

Flowering Jun-Sep. Sandy to gravelly flats and slopes, sagebrush communities, montane conifer woodlands; 800-1800 m; Idaho, Oreg., Wash.

Variety devestivum is a glabrous-leaved expression obviously related to var. ellipticum. It is infrequently encountered in Asotin and Columbia counties, Washington; Baker, Grant, and Union counties, Oregon; and Ada, Adams, Blaine, Lemhi, Valley, and Washington counties, Idaho. The plants are bright and showy and would be attractive in the garden.