Shrubs, 3–5 m. Stems: branches gray-brown or red-brown, hairy or glabrous; branchlets red-brown, densely villous. Leaves: stipules absent or rudimentary on early ones, rudimentary or foliaceous on late ones (apex acute); petiole 1–6 mm, long-silky adaxially; largest medial blade (sometimes hypostomatous, glands submarginal), linear, lorate, narrowly elliptic, or narrowly oblanceolate, 40–120 × 7.5–16 mm, 3–8.5 times as long as wide, base cuneate or convex, margins flat, remotely spinulose-serrulate, apex acuminate, acute, or caudate, abaxial surface not glaucous, densely to sparsely long- or short-silky or villous, hairs appressed or spreading, straight or wavy, adaxial dull, sparsely long-silky or villous; proximal blade margins entire; juvenile blade yellowish green, very densely long-silky or villous abaxially. Catkins: staminate 38–45 × 6–7 mm, flowering branchlet 25–45 mm; pistillate densely flowered, slender, 40–73 × 6–7 mm, flowering branchlet 20–32 mm; floral bract (sometimes brown), 2.4–3.2 mm, apex acute or rounded, entire or irregularly toothed, abaxially hairy, hairs wavy. Staminate flowers: abaxial nectary 0.4–1 mm, adaxial nectary narrowly oblong, oblong, or flask-shaped, 0.5–1.1 mm, nectaries distinct; filaments hairy on proximal 1/2; anthers 0.8–1.2 mm. Pistillate flowers: adaxial nectary oblong, square, ovate, or flask-shaped, 0.6–1 mm, longer than stipe; stipe 0.2–0.7 mm; ovary pyriform, villous or long-silky, beak abruptly tapering to styles; ovules 24–36 per ovary; styles 0.1–0.7 mm; stigmas flat, abaxially non-papillate with pointed tip, or slenderly cylindrical, 0.4–1 mm. Capsules 4–5.5 mm.
Phenology: Flowering late Apr-late May.
Habitat: Riparian, streamshores, floodplains, sandy or gravelly substrates
Elevation: 0-200 m
B.C., Oreg., Wash.
Salix sessilifolia forms natural hybrids with S. columbiana and S. melanopsis.