Flora of North America species comparison

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

lenticels inconspicuous.

thin, close or exfoliating in thin sheets, becoming thicker and frequently furrowed or broken in age;

lenticels often present, prominent, sometimes becoming greatly expanded horizontally.;

bark and wood strongly tanniferous.

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.

3-ranked, occasionally nearly 2-ranked.

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.

perianth of 4(–6) sepals, well defined, minute, membranaceous.

2–3 per scale, scales arranged in conelike catkins;

perianth not obvious;

ovules with 1 integument.

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

peduncles 5–10 mm.

1–4 cm, conelike, composed of many scales;

scales either persistent or deciduous with fruits, crowded, small, woody or leathery.

tiny samaras, lateral wings 2, membranous, sometimes reduced to ridges;

pericarp thin, leathery.

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.

before new growth in spring.

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

and branches terete.

twigs and buds often covered with small to large, resinous glands;

pith triangular in cross section.