Flora of North America species comparison

branches divaricate, sometimes ± brittle at base, yellow-brown to dark red-brown, not or weakly glaucous, pilose to glabrescent, peeled wood often with very dense striae, to 25 mm;

branchlets yellow-green or red-brown, moderately to very densely villous to glabrescent.

stipules rudimentary or absent on early ones, apex acute, acuminate, or convex;

petiole convex to flat adaxially, 2–5.5–13 mm, pubescent adaxially;

largest medial blade narrowly oblong, narrowly elliptic, elliptic, oblanceolate, or obovate, 20–44–87 × 10–16–45 mm, base cuneate, convex, or rounded, margins flat, entire, crenate, or irregularly serrate, glands submarginal, apex acute, acuminate, or convex, abaxial surface glaucous, moderately densely pubescent or long-silky to glabrescent, hairs white or gray, wavy, adaxial finely impressed-reticulate, dull or slightly glossy, moderately densely pubescent, sparsely short-silky, or glabrescent, hairs white or gray;

proximal blade margins entire, gland-dotted;

juvenile blade yellowish green or reddish, pilose or sparsely to moderately densely tomentose or long-silky abaxially, hairs white.

stipules absent or rudimentary on early ones, foliaceous or rudimentary on late ones;

petiole 1–5(–10) mm, pubescent or puberulent, villous, or short-silky adaxially;

largest medial blade (sometimes hypostomatous), linear or lorate, (glands marginal), 30–136–143 × 2–14 mm, 6.5–28(–37.5) times as long as wide, base cuneate, margins slightly revolute, entire or remotely spinulose-serrulate, apex acuminate or acute, abaxial surface glaucous (sometimes obscured by hairs), densely long-silky, villous or pilose to glabrescent, hairs appressed or spreading, straight or wavy, adaxial slightly glossy, sparsely or densely long-silky to glabrescent;

proximal blade margins entire;

juvenile blade yellowish green, densely long-silky-villous abaxially.

adaxial nectary oblong or ovate, 0.3–0.8 mm;

filaments distinct or connate less than 1/2 their lengths, glabrous or hairy on proximal 1/2;

anthers yellow or purple turning yellow, ellipsoid or shortly cylindrical, 0.5–0.8 mm.

abaxial and adaxial nectaries present and distinct;

filaments hairy on proximal 1/2;

anthers (sometimes reddish turning yellow).

adaxial nectary oblong or square, 0.3–0.8 mm;

ovary obclavate, beak slightly bulged below styles (long-beaked);

ovules 6–16 per ovary;

styles 0.1–0.4 mm;

stigmas slenderly to broadly cylindrical.

adaxial nectary oblong, ovate, or flask-shaped, relative adaxial nectary/stipe length variable even within same catkin;

stipe 0–0.9 mm;

ovary obclavate or pyriform, glabrous, pilose, or villous, or sometimes beak hairy, beak bulged below or abruptly tapering to styles;

ovules 12–30 per ovary;

styles (sometimes distinct), 0–0.5 mm;

stigmas flat, abaxially non-papillate with rounded tip, or 2 plump lobes, 0.1–0.5 mm.

5–9 mm.

4–8 mm.

staminate flowering just before leaves emerge, pistillate flowering as leaves emerge; staminate stout to globose, 10–42 × 7–16 mm, flowering branchlet 0.5–11 mm; pistillate loosely flowered, stout, slender, or subglobose, 16.5–85 × 9–32 mm, flowering branchlet 1–26 mm;

floral bract tawny, 1.2–3.2 mm, apex rounded, abaxially hairy to glabrescent, hairs straight or wavy.

staminate 7–54 × 2–10 mm, flowering branchlet 1.5–56 mm; pistillate loosely to densely flowered, slender or stout, 14.5–70 × 3–12 mm, flowering branchlet 2–55 mm;

floral bract 1.2–2.6 mm, apex acute, convex, or rounded, entire or erose, hairs wavy, straight, or crinkled, abaxially hairy throughout or proximally, or glabrate.

= 38.

= 38.