Flora of North America species comparison

dark brown, smooth, becoming darker and breaking into shallow fissures in age;

lenticels pale, horizontal.

blade obovate to nearly orbiculate, 3–9 × 3–8 cm, leathery, base obtuse to broadly cuneate, margins flat, coarsely and often irregularly doubly serrate to nearly dentate, major teeth acute to obtuse or rounded, apex often retuse or obcordate, or occasionally rounded;

surfaces abaxially glabrous to sparsely pubescent, often more heavily on veins, both surfaces heavily resin-coated.

blade broadly to narrowly ovate or elliptic, 3–11 × 3–8 cm, base rounded, obtuse, or cuneate, sometimes nearly cordate, margins serrulate to coarsely doubly serrate, apex acute to rounded;

surfaces abaxially glabrous to tomentose, lightly to heavily resin-coated.

formed season before flowering and exposed during winter; staminate catkins in 1 or more clusters of 2–5, 4–13 cm; pistillate catkins in 1 or more clusters of 2–5.

staminate catkins in 1 cluster of 2–4, formed late in growing season before flowering and exposed during winter; pistillate catkins in 1 or more clusters of 2–10, formed season before blooming, enclosed in buds during winter, exposed with new growth in spring.

ovoid to nearly globose, 1.2–2.5 × 1–1.5 cm;

peduncles 1–10(–20) mm.

ovoid to ellipsoid or nearly cylindric;

peduncles relatively long, thin.

buds stipitate, ellipsoid to obovoid, 6–10 mm, apex obtuse;

stalks 2–5 mm;

scales 2–3, outer 2 equal, valvate, usually heavily resin-coated.

buds nearly sessile, ovoid, apex acuminate;

stalks usually not over 1 mm;

scales 4–6, unequal, imbricate.

before new growth in spring.

with new growth in spring.

obovate, wings reduced to narrow, thickened ridges.

elliptic to obovate, wings wider than body, membranaceous.

= 28.