Novon 12: 321. 2002.
Perennials; caudex simple or branched, (woody, cespitose); ± densely pubescent, trichomes (sessile or short-stalked), several-rayed, rays distinct, furcate or bifurcate, (somewhat umbonate, finely tuberculate to ± smooth). Stems simple or few to several from base, erect to spreading or prostrate, 0.5–2(–3) dm. Basal leaves (usually ± rosulate); blade obovate to oblanceolate, (1–)2–6(–15) cm, margins entire. Cauline leaves (sessile or shortly petiolate); blade oblanceolate or lingulate, 0.5–1.5(–3) cm, margins entire. Racemes loose. Fruiting pedicels (erect to divaricate or ascending), (5–)10–20(–40) mm, (stout). Flowers: sepals ovate to elliptic, (3–)4–5(–6) mm, (median pair often thickened apically, cucullate); petals spatulate, 5–6(–7) mm, (blade gradually narrowed to claw). Fruits subglobose to ellipsoid, uncompressed, 4–6(–9) mm; valves (not retaining seeds after dehiscence), glabrous or sparsely pubescent outside, trichomes sessile; replum as wide as or wider than fruit; ovules (8–)10–14(–16) per ovary; style 1–2.5(–4) mm. Seeds plump. 2n = 60.
Phenology: Flowering May–Aug.
Habitat: Typically on sand and gravel from calcareous bedrock, river bars and terraces, cliff ledges, scree and talus slopes, often growing after disturbance
Elevation: 0-1800 m
Greenland, Alta., B.C., Man., Nfld. and Labr., N.W.T., Nunavut, Que., Yukon, Alaska, circumarctic (except n Europe, ne Russia).