2. Potentilla biflora D. F. K. Schlechtendal, Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 7: 297. 1816.
Two-flower cinquefoil
Basal leaves: petiole 1–4 cm, long hairs absent or sparse, 1.5–2 mm, crisped hairs absent or sparse; leaflet lobes linear, 10–20 × 1–2 mm, surfaces with long hairs sparse or absent. Flowers: epicalyx bractlets oblong, ovate, or lanceolate, 2.5–4 × 0.4–1.3 mm; sepals 3.5–5 mm, apex acute to apiculate; petals 6–10 × 4–10 mm; filaments 2.8–4 mm, anthers 0.6 mm; carpels 15–25. Achenes 1.5–2 mm. 2n = 14.
Flowering summer. Dryas fellfields, gravel terraces, well-drained soil, often with seasonal seepage, on calcareous substrates; 0–2000 m; B.C., N.W.T., Nunavut, Yukon; Alaska; Asia.
In North America, Potentilla biflora is mostly Beringian, barely reaching northern British Columbia and western Northwest Territories, with one locality in Nunavut (southern Victoria Island). The amphi-Beringian range is strongly isolated from other Asian populations, the closest being in the Altai Mountains of south-central Siberia. Two varieties are accepted in China (Li C. L. et al. 2003c), with North American plants falling in var. biflora.