Diamond-leaf willow

Salix divaricata Pallas subsp. pulchra (Chamisso) Voroschilov; S. phylicifolia Linnaeus subsp. pulchra (Chamisso) Hultén; S. phylicifolia var. subglauca (Andersson) B. Boivin; S. planifolia Pursh subsp. pulchra (Chamisso) Argus; S. planifolia var. yukonensis (C. K. Schneider) Argus; S. pulchra var. yukonensis C. K. Schneider

Shrubs, 0.1-3(-4.5) m. Stems: branches yellow-brown or red-brown, not or weakly glaucous, (slightly or highly glossy), villous in patches to glabrescent; branchlets yellow-green or brownish, glabrous, puberulent, or densely villous, (buds caprea- or arctica-type). Leaves: stipules (usually marcescent), foliaceous, (linear or lanceolate, 2-9.8-23 mm), apex acuminate; petiole convex to flat adaxially, 2.8-10(-15) mm, glabrous or puberulent adaxially; largest medial blade narrowly elliptic, elliptic, or obovate, 22-75 × 8-26 mm, 1.7-4.7 times as long as wide, base cuneate, margins flat to slightly revolute, entire, crenate, or serrulate, apex acuminate, acute, or convex, abaxial surface glaucous, glabrous or pubescent, midrib pilose, hairs (white, sometimes also ferruginous), straight, adaxial highly to slightly glossy, midrib glabrous or sparsely pubescent; proximal blade margins entire; juvenile blade green, glabrous or pubescent abaxially, hairs white, sometimes also ferruginous. Catkins flowering before leaves emerge; staminate stout or subglobose, 21-53 × 12-19 mm, flowering branchlet 0-3 mm; pistillate densely flowered, slender to stout, 27-82 × 8-20 mm, flowering branchlet 0-3(-8) mm; floral bract brown or black, 1.6-2.8 mm, apex acute or rounded, abaxially hairy distally, hairs straight. Staminate flowers: adaxial nectary narrowly oblong to oblong, 0.6-1 mm; filaments distinct or connate less than 1/2 their lengths, glabrous; anthers purple turning yellow, ellipsoid to shortly cylindrical, 0.4-0.8 mm. Pistillate flowers: adaxial nectary narrowly oblong to oblong, 0.4-1.6 mm, longer than stipe; stipe 0.2-0.8 mm; ovary pyriform, long-silky, beak slightly bulged below styles; ovules 12-16 per ovary; styles 1-1.8 mm; stigmas slenderly cylindrical, 0.44-0.63-0.96 mm. Capsules 3.2-5.6 mm. 2n = 76.

Flowering mid Apr-late Jul. Arctic boreal and subalpine thickets, stream and lake margins, tundra, black spruce-lichen woodlands, open white spruce-dwarf birch woodlands; 0-2000 m; B.C., N.W.T., Nunavut, Yukon; Alaska; Asia (Chukotka, Kamchatka, Lena-Kolyma, Okhotia, Russia [Anadyr], Siberia).

Plants with branchlets densely villous with white, gray, or, sometimes, ferruginous hairs have been named var. yukonensis. This hairy variant occurs scattered throughout populations in both North America and Russia and does not seem to warrant taxonomic recognition. The closely related Salix planifolia shows similar variation.

Hybrids:

Salix pulchra forms natural hybrids with S. planifolia and S. scouleriana.

Salix pulchra × S. scouleriana is known from Alaska. It resembles S. pulchra in its long, linear stipules, general leaf shape, and relatively long styles; and S. scouleriana in its juvenile leaves with abundant ferruginous hairs, petioles densely villous to velvety, and relatively short stigmas.