Perennials; (cespitose, pulvinate); caudex often branched (covered with persistent, thickened petioles, branches sometimes terminating in sterile rosettes); scapose. Stems unbranched, (0.04-)0.07-0.5(-0.6) dm, usu-ally pubescent throughout, rarely glabrous distally, tri-chomes simple and 2-rayed, 0.2-0.6 mm, with smaller, dendritic ones. Basal leaves (densely imbricate); rosulate; petiolate; petiole margin ciliate, (trichomes simple and 2-rayed, 0.3-0.8 mm); blade oblanceolate to obovate or nearly linear, 0.2-0.8(-1.1) cm × 1-3 mm, margins entire, (pubescent as abaxial surface), surfaces pubescent abaxially, glabrous adaxially, with simple and stalked, 2-rayed trichomes, 0.3-0.8 mm, sometimes with subdendritic ones, 0.1-0.3 mm, (midvein persistent, strongly thickened). Cauline leaves 0. Racemes 2-8-flowered, ebracteate, (corymbose), slightly elongated in fruit; rachis not flexuous, usually pubescent as stem, (trichomes often crisped), rarely glabrous. Fruiting pedicels horizontal to divaricate, straight, 1-5(-7) mm, usually pubescent as rachis, rarely glabrous. Flowers: sepals oblong, 1.2-1.8 mm, pubescent, (trichomes simple); petals white or creamy white, spatulate, 1.5-2(-2.5) × 0.7-1 mm; anthers ovate, 0.2-0.3 mm. Fruits ovoid to oblong, plane, slightly inflated, 3.5-6 × 2-3 mm; valves usually glabrous, rarely puberulent, trichomes simple, 0.05-0.15 mm; ovules 14-24 per ovary; style 0.1-0.3 mm. Seeds oblong, 0.9-1.1 × 0.5-0.6 mm. 2n = 16. Flowering Jul-Aug. Talus slopes, limestone barrens, peaty bluffs, silty slopes, seepage areas, disturbed gravel; 0-1000 m; Greenland; N.W.T., Nunavut, Que.; Alaska; Europe (Norway, n Sweden); e Asia (Russian Far East, Siberia).