Plants slender, 0.5-1.5(-1.9) dm. Leaves slightly dimorphic; basal 2, blade linear, 4-10(-20) cm × 0.8-1 mm; cauline 2-4, blade lanceolate, 1-5 × 0.1-0.2 cm. Flowers 1-2; tepals 0.9-1.2(-1.4) cm; stamens erect; filaments 3-8 mm; anthers 0.6-1(-1.2) mm. Capsules 6-8 mm.

Perianth yellow with yellowish to greenish veins. 2n = 24.

Flowering summer (Jun--Sep). Rocky slopes and exposed habitats of subalpine zones; 100--1000 m; B.C.

Variety flava from the Queen Charlotte Islands (Graham and Moresby islands) differs from the typical variety in floral color and is more robust with well-developed leaves that nearly always exceed the flowering or fruiting scapes (J. A. Calder and R. L. Taylor 1965).

Perianth white with greenish to purplish veins. 2n = 24, 36, 48.

Flowering summer (Jun--Sep). Gravelly to rocky slopes and cliff faces or rock crevices, grassy tundra; 400--4400 m; B.C., N.W.T., Yukon; Alaska, Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo.; Eurasia.

Variety serotina, the typical, arctic-alpine variety (T. Irmisch 1863; B. Jones and C. Gliddon 1999), is wide-ranging throughout the Northern Hemisphere (N. Woodhead 1951).