Flora of North America species comparison

rough, furrowed, fibrous.

smooth at first, later building up in layers.

comblike, 0.5–1 mm diam.

decussate, 0.5–1.3 mm diam.

with conspicuous, pitlike, abaxial gland that produces drop of resin, sometimes glaucous.

with conspicuous, pitlike, abaxial gland that produces drop of resin, slightly glaucous.

2–3 × 2 mm;

pollen sacs 3–5.

2–3 × 2–2.5 mm;

pollen sacs 3–5.

cones globose, mostly 1.5–2.5 cm, brown or gray, not glaucous;

scales 3–4 pairs, smooth except for erect conic umbos, 2–4 mm.

cones globose, mostly 1–2 cm, silvery, not glaucous;

scales 3–4 pairs, usually covered with resin blisters, umbos often prominent, those of distal scales erect, to 4 mm.

trees to 12 m;

crown broadly conical, dense.