Shrubs, 0.8-4 m. Stems: branches gray-brown or red-brown, glabrous or hairy; branchlets gray-brown to dark red-brown, glabrous, puberulent, densely long-silky, or villous to glabrescent. Leaves: stipules absent, rudimentary, or foliaceous on early ones, foliaceous on late ones (apex acuminate); petiole 1.5-8 mm, glabrous adaxially; largest medial blade lorate, narrowly oblong, narrowly elliptic, narrowly oblanceolate, or linear, 30-133 × 5-20 mm, 3.4-8-15 times as long as wide, base cuneate or convex, margins flat, spinulose-serrulate or entire, apex acute, acuminate, or convex, abaxial surface glaucous or not, pilose, villous, or long-silky to glabrescent, hairs appressed or spreading, wavy, adaxial slightly glossy, villous to glabrescent; proximal blade margins entire or serrulate; juvenile blade reddish or yellowish green, densely villous abaxially. Catkins: staminate 18-48 × 5-13 mm, flowering branchlet 3-15 mm; pistillate moderately densely flowered, slender or stout, 22-58 × 4-9 mm, flowering branchlet 4-12 mm; floral bract (sometimes brown), 1.3-2.8 mm, apex rounded (sometimes truncate), entire or erose, abaxially hairy mainly proximally, hairs wavy. Staminate flowers: abaxial nectary 0.3-0.9 mm, adaxial nectary narrowly oblong, oblong, or flask-shaped, 0.4-1.2 mm, nectaries distinct; filaments densely hairy on proximal 1/2; anthers 0.55-0.7-0.9 mm. Pistillate flowers: adaxial nectary ovate, oblong, or flask-shaped, 0.4-1.1 mm, longer than stipe, nectaries distinct or connate and cup-shaped; stipe 0-0.7 mm; ovary obclavate or pyriform, glabrous, beak abruptly tapering to styles; ovules 13-22 per ovary; styles 0-0.14-0.5 mm; stigmas slenderly cylindrical or 2 plump lobes, 0.2-0.5 mm. Capsules 4-5 mm. Flowering early May-mid Jul. Riparian, floodplains, stream banks, subalpine meadows, coarse-textured substrates, silt; 600-3100 m; Alta., B.C.; Calif., Colo., Idaho, Mont., Nev., Oreg., Wash., Wyo. Salix fluviatilis Nuttall, long used for a Columbia River endemic (see 22. S. columbiana), is a rejected name.
Salix melanopsis forms natural hybrids with S. exigua var. exigua, S. sessilifolia, and S. sitchensis (R. D. Dorn 1998).