Plants perennial, taprooted; caudex branching. Stems 1 from each rosette, ascending to erect, to 60 cm. Leaves: basal in 2-many prostrate rosettes, blade spatulate, (0.5-)2-7(-15) cm; cauline leaves usually absent. Inflorescences umbellate or subumbellate, dense, globose, 1-2 cm diam. Flowers subsessile; sepals orbiculate, equal, 3-8 mm, scarious; petals 4, white, 3-8 mm; stamens 3, anther red or yellow; style exserted, filiform; stigmas 2. Capsules globose, 2-3 mm; valves 2. Seeds 1-8, black, orbicular-reniform, 0.7-1.2 mm, shiny. 2n = 44. Flowering May-Oct. Dry sandy or gravelly soils; 1500-4300 m; B.C.; Calif., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.