Cardamine nymanii Gandoger, Bull. Soc. Bot. France 72: 1043. 1925. TYPE:

Cardamine pratensis Linnaeus var. angustifolia W. J. Hooker, App. Parry J. Sec. Voy. 389. 1825; C. pratensis subsp. angustifolia (W. J. Hooker) O. E. Schulz, Bot. Jahrb. Syst. 32: 529. 1903. TYPE:

Cardamine pratensis subsp. polemonioides Rouy

Herbs perennial, glabrous. Rhizomes caespitose; stolons absent. Stems 0.5–1.6(–3.5) dm, erect, simple, rarely branched. Leaves thick, with impressed veins; rhizomal leaves with terminal leaflets of the same size and shape as lateral ones, orbicular, broadly ovate to lanceolate, base rounded to cuneate, mostly entire, petiolulate or sessile, (7 or)9–21-foliolate; cauline leaves 2–4(–7), pinnatisect or pinnately compound and (7 or)9–21-foliolate, glabrous; petiole base not auriculate; terminal segments or leaflets of the same shape as lateral ones, narrowly lanceolate to lanceolate, petiolulate or sessile, base cuneate, margin entire; lateral lobes or leaflets of lower leaves (4–)7–10 on each side of rachis, fewer upwards, upper leaves with 4 or 5 segments or leaflets on each side of rachis. Racemes ebracteate; fruiting pedicels erect-ascending, 5–15 mm. Sepals oblong or ovate, 3.6–4.4 mm, erect, base saccate, green with hyaline margin; petals white-lilac 9–12.3 × 4.8–6.8 mm, clawed, apex rounded or emarginate; median filament pairs 3.5–4.5 mm, lateral 2–3 mm; anthers narrowly oblong 0.9–1.4 mm. Fruit linear, 1–1.8 cm × ca. 1.5 mm; valves glabrous; style ca. 1 mm, stout; ovules and seeds ca. 16 per fruit. Seeds brown, oblong, ca. 1.5 mm. 2n = 56, 60, 64, 80–100.

Flowering: Jun–Aug.

Habitat: wet meadows, marshes, margins of ponds, along rivers and streams, often along sea costs, swamps.

Distibution: Canada (Labrador, N Manitoba, Newfoundland, Northwest Territories, Nunavut, Quebec, Yukon), Europe (Finland, Island, Norway, Sweden), Greenland, Russia (N European part, Siberia), United States (Alaska). n Eurasia.