Flora of North America species comparison

dark gray, smooth, becoming blackish and breaking into shallow vertical plates in age;

lenticels inconspicuous.

light gray, smooth;

lenticels small, inconspicuous.

blade narrowly ovate or lanceolate to narrowly elliptic, 5–9 × 3–6 cm, leathery, base narrowly to broadly cuneate or narrowly rounded, margins flat, sharply and coarsely doubly serrate, rarely evenly and densely short-serrate, major teeth sharp, acuminate, secondary teeth distinctly larger, apex long to short-acuminate, rarely acute;

surfaces abaxially glabrous to sparsely pubescent or infrequently villous, moderately resin-coated.

blade narrowly elliptic, oblong, or narrowly obovate, 4.5–9 × 2–5 cm, leathery, base acute to cuneate, margins flat, teeth low, single, relatively distant, apex acute, obtuse, or rounded;

surfaces abaxially mostly glabrous, resin-coated when young.

formed season before flowering and exposed during winter; staminate catkins in 1 or more clusters of 3–6, 3.5–10 cm; pistillate catkins in 1 or more clusters of 2–7.

catkins formed during same season as flowering; staminate catkins in 1 terminal cluster of 2–4, 2–6 cm; pistillate catkins solitary in leaf axils proximal to staminate catkins.

ovoid, ellipsoid, or nearly cylindric, 1–2.5 × 0.8–1.5 cm;

peduncles 5–10 mm.

ovoid, 1.2–2.8 × 1.2–2.2 cm;

peduncles 5–10 mm.

buds stipitate, ovoid, 4–8 mm, apex rounded;

stalks 1.5–4 mm;

scales 2, equal, valvate, sometimes incompletely covering underlying leaves, moderately resin-coated.

buds stipitate, ovoid to ellipsoid, 2.5–5 mm, apex rounded;

stalks 1–3 mm;

scales 2–3, subequal, often poorly developed, heavily resin-coated.

before new growth in spring.

in late summer or early fall.

elliptic to obovate, wings narrower than body, irregular in shape, leathery.

elliptic, wings reduced to narrow, leathery ridges.

= 28.