Strap-leaf willow

Salix lutea Nuttall var. ligulifolia C. R. Ball, Bot. Gaz. 71: 428. 1921; S. eriocephala Michaux var. ligulifolia (C. R. Ball) Dorn

Shrubs, 1-8 m. Stems: branches yellow-brown, gray-brown, or red-brown, not glaucous, glabrous or villous; branchlets yellow-green or yellow-brown, glabrous, sparsely to densely villous, or velvety, (inner membranaceous bud-scale layer free, not separating from outer layer). Leaves: stipules foliaceous, apex rounded, convex, acute or acuminate; petiole convex to flat, or shallowly grooved adaxially, 3-18 mm, glabrous, pilose, or velvety to glabrescent adaxially; largest medial blade lorate, narrowly oblong, or narrowly elliptic, 60-133 × 12-30 mm, 2.9-6.4 times as long as wide, base rounded, convex, or subcordate, margins flat, usually serrulate or serrate, rarely (apparently) entire, apex acuminate to acute, abaxial surface glaucous, glabrous, sparsely short-silky or pubescent, hairs straight or wavy, adaxial dull, glabrous, sparsely short-silky, or midrib pubescent; proximal blade margins entire, serrulate, or crenulate; juvenile blade reddish or yellowish green, glabrous or sparsely to moderately densely pilose or puberulent abaxially, hairs white. Catkins flowering as or just before leaves emerge; staminate stout, 20.5-34 × 8-11 mm, flowering branchlet 0-3 mm; pistillate moderately densely flowered, slender to subglobose, 15.5-49 × 8-18 mm, flowering branchlet 1-6 mm; floral bract brown or bicolor, 0.8-1.6 mm, apex acute or rounded, abaxially hairy throughout or proximally (hairs usually arising from rachis), hairs wavy or curly. Staminate flowers: adaxial nectary narrowly oblong, oblong, flask-shaped, or triangular, 0.3-0.8 mm; filaments distinct or connate less than 1/2 their lengths (or appearing as a single stamen), glabrous or hairy basally; anthers purple or red turning yellow, (ellipsoid or globose), 0.5-0.8 mm. Pistillate flowers: adaxial nectary oblong, narrowly oblong, or flask-shaped, 0.3-0.9 mm, shorter than stipe; stipe 0.9-2.5 mm; ovary pyriform, glabrous, beak sometimes slightly bulged below styles; ovules 12-21 per ovary; styles 0.2-0.6 mm; stigmas flat, abaxially non-papillate with rounded tip, or slenderly cylindrical, 0.16-0.25-0.4 mm. Capsules 4-6 mm. 2n = 38.

Flowering late Mar-mid Jun(-late Jul). Banks and floodplains, cienegas, sandy-clay or gravelly substrates; 0-3100 m; Ariz., Calif., Colo., N.Mex., Oreg., Utah, Wyo.

Salix ligulifolia sometimes has leaf teeth that are so short that it is referred to as "entire-leaved." That condition is uncommon and, even when some leaves appear to be entire, others with fine serrulations can be found on the same plant.

Hybrids:

Salix ligulifolia forms natural hybrids with S. geyeriana.