54a. Salix wolfii Bebb var. wolfii
Plants 0.5-2 m. Stems: branches red-brown or violet, pubescent to glabrescent; branchlets yellow-brown or yellowish, sparsely pubescent or densely long-silky, hairs straight, wavy, curved, or crinkled. Leaves: petiole convex to flat, or shallowly grooved adaxially, 3-5.6 mm, pubescent or long-silky adaxially; largest medial blade narrowly oblong, narrowly elliptic, elliptic, or oblanceolate, apex acute, acuminate, or convex, abaxial surface pubescent, short-silky, or villous, adaxial sparsely to densely short- to long-silky, or villous; juvenile blade short- to long-silky or villous abaxially. Catkins: pistillate moderately or very densely flowered, subglobose or globose, 8.5-19 × 7-12 mm, flowering branchlet 1-7 mm; floral bract 0.8-1.6 mm. Staminate flowers: abaxial nectary (0-)0.1-0.2 mm, adaxial nectary 0.4-0.5 mm. Pistillate flowers: adaxial nectary oblong, 0.4-0.8 mm, shorter to longer than stipe; stipe 0.2-0.9 mm; ovary glabrous; ovules 10-12 per ovary; stigmas flat, abaxially non-papillate with rounded or pointed tip. 2n = 38.
Flowering early-mid Jun. Stream banks, springs, wet meadows, bogs; 2000-3800 m; Colo., Idaho, Mont., Nev., Oreg., Utah, Wyo.
Variety wolfii forms natural hybrids with Salix boothii.