Plants perennial, cespitose, glabrous to sparsely pubescent, nonviscid; taproot stout. Stems erect, simple, 5-35 cm, glabrous or very sparsely short-pubescent. Leaves: basal crowded, blade narrowly oblanceolate, 1-5 cm × 1-5 mm, tapered into broad ciliate base, apex acute; cauline in 2-5 pairs, sessile, connate proximally, blade narrowly lanceolate, 1-4 cm × 2-7 mm, margins ciliate, apex acute. Inflorescences cymose, congested, 6-30-flowered, bracteate, pedunculate, often with smaller pedunculate branches in distal nodes; bracts purple, lanceolate, 2-20 mm; peduncle glabrous to sparsely puberulent. Pedicels glabrous to sparsely puberulent. Flowers sessile or short-petiolate, 5-10 mm diam.; calyx purple, faintly 10-veined, campanulate, 4-6 × 3-5 mm, base attenuate into pedicel, lobes ovate, 1-1.5 mm, margins broad, membranous, apex obtuse; corolla bright pink (rarely white), limb spreading, 2-lobed to middle, 3.5-7 mm, cuneate into claw, ca. 11/ 1/ 2 times calyx, appendages absent; stamens ca. equaling petals; stigmas 5, ca. equaling petals. Capsules ovoid, equaling to slightly longer than calyx, opening by 5 recurved teeth; carpophore ca. 1 mm. Seeds dark brown, reniform, 0.5-0.8 mm, verrucate with crescent-shaped pattern. 2n = 24.

Flowering summer. Tundra, rocky barrens, gulleys and river outwashes, grassy slopes, sea cliffs; 0-1100 m; Greenland; Nfld. and Labr., Nunavut, Que.; Europe (Iceland).

North American material of this arctic-alpine species has been regarded as distinct at the varietal and subspecific levels (M. L. Fernald 1940b; T. W. Böcher 1963) because it tends to be larger. However, the distinction is arbitrary, and some European material is as large as that from North America. A recent electrophoretic study (K. B. Haraldsen and J. Wesenberg 1993) of allozymes in populations from both continents provides no support for subdivision of this species.