Plants 0.3-1 m. Stems: branches gray-brown to red-brown, densely villous; branchlet color obscured by hairs, densely villous. Leaves: stipules sometimes marcescent, foliaceous (sometimes obscured by hairs) on early ones, foliaceous and prominent on late ones, linear to narrowly elliptic, 2-17 mm, apex acute to caudate; petiole 1-9 mm, villous adaxially; largest medial blade (hemiamphistomatous), sometimes narrowly oblong, 27-74 × 8-24 mm, 2.1-3.9 times as long as wide, base rounded, apex acuminate, convex, or acute, abaxial surface densely villous or villous-silky, hairs straight or wavy, adaxial moderately densely villous, or long-silky to glabrescent; proximal blade margins entire; juvenile blade densely villous or long-silky. Catkins: staminate 14-26 × 8-14 mm, flowering branchlet 1-14 mm; pistillate stout or subglobose, 15-54 × 7-15 mm, flowering branchlet 2-19 mm; floral bract tawny, light brown or bicolor, 1.2-2.2 mm, apex convex, hairs straight, wavy, or crinkled. Staminate flowers: abaxial nectary 0.3-1 mm; filaments distinct or partly connate, glabrous, or hairy on proximal 1/2. Pistillate flowers: adaxial nectary sometimes flask-shaped, (0.4-)0.6-1.8 mm; stipe 0.4-1.8 mm; ovary obclavate or pyriform, very densely villous or tomentose, beak abruptly tapering to styles; ovules 10-20 per ovary; styles connate to distinct, 0.4-1 mm; stigmas slenderly cylindrical, 0.3-0.8 mm. Capsules 4.5-7.5 mm. 2n = 76, 114, 152. Flowering mid Jun-mid Jul. Black spruce treed bogs, white spruce woods, floodplains, subarctic thickets, alpine tundra; 0-1000 m; N.W.T, Nunavut, Yukon; Alaska; Eurasia (China, n Mongolia, Russia, Scandinavia). Hybrids:

Variety stipulata forms natural hybrids with Salix arctica, S. arctophila, and probably others.