Flora of North America species comparison

light gray, smooth, becoming darker and breaking into scales 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 elliptic to rhombic, rarely ovate, 4–9 × 2–5 cm, base cuneate to rounded, margins flat, finely serrate or serrulate, sometimes slightly lobed, without noticeably larger secondary teeth, apex acute or obtuse to rounded;

surfaces abaxially sparsely pubescent to villous.

3-ranked, occasionally nearly 2-ranked.

formed season before flowering and exposed during winter; staminate catkins in 1 or more clusters of 3–7, 3–10 cm, stamens 2, or 4 with 2 reduced in size; pistillate catkins in 1 or more clusters of 2–6.

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 to nearly cylindric, 1–2.2 × 0.7–1 cm;

peduncles 1–10 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, ellipsoid to obovoid, 3–9 mm, apex rounded;

stalks 3–5 mm;

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

before new growth in spring.

broadly elliptic, 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.