Plants 0.05-1.3 m, (gnarled, sometimes forming clones by layering). Stems: branches yellow-brown, gray-brown, or red-brown, not to weakly glaucous (dull or slightly glossy), villous to glabrescent; branchlets yellow-brown or red-brown, moderately densely to sparsely villous, (buds caprea- or arctica-type, scale inner membranaceous layer free, separating from outer layer in var. calcicola). Leaves: stipules (sometimes marcescent), foliaceous, (1-6-14 mm, 1.1-2-4.4 times as long as wide, usually ovate, oval, or narrowly elliptic, flat when pressed), apex acute, convex, or rounded; petiole shallowly grooved, or convex to flat adaxially, 1.5-3.8-9 mm, villous or pilose adaxially; largest medial blade (sometimes hemiamphistomatous), narrowly to broadly elliptic or subcircular, 16-31.5-61 × 10- 21.8-44 mm, 0.7-1.5-2.6 times as long as wide, base rounded or convex, sometimes cordate or cuneate, margins (sometimes purplish), flat, entire or serrulate, apex acuminate, acute, or rounded, abaxial surface glaucous, sparsely villous or pilose to glabrescent, hairs straight, adaxial dull or slightly glossy, sparsely villous or pilose; proximal blade margins entire; juvenile blade reddish or yellowish green, moderately densely villous abaxially, hairs white. Catkins flowering before leaves emerge; staminate (no data on var. glandulosior) stout, 18-45 × 13-21 mm, flowering branchlet 0 mm; pistillate (no data on var. glandulosior except flowering branchlet length) densely flowered, stout, 32-75(-100 in fruit) × 12-25 mm, flowering branchlet 0-5 mm; floral bract brown or black, 1.2-3.2 mm, apex rounded or acute, abaxially hairy, hairs straight. Staminate flowers: adaxial nectary oblong or narrowly oblong, 0.5-1.2 mm; filaments distinct, glabrous; anthers purple turning yellow, ellipsoid or shortly cylindrical, 0.5-0.7 mm. Pistillate flowers: adaxial nectary oblong, 0.2-1.1 mm, longer than or equal to stipe (rarely shorter); stipe 0.2-1.2 mm; ovary pyriform or obclavate, beak gradually tapering to styles; ovules 13-20 per ovary; styles 0.9-3 mm; stigmas broadly cylindrical, 0.2-0.56 mm. Capsules 4-8 mm.