Habit: small tree

Leaves: often glaucous, blue or blue-gray, scale-like, entire margins

Reproductive Structure: bluish and glaucous berry-like seed cones, dark blue below waxy coating, globose to 2-lobed and resinous

Habitat: Rocky Mountain forests

Habit: medium willow-like tree

Leaves: lanceolate, apex acuminate, base rounded, margin serrulate, glabrous or nearly so, shiny green above, paler below, short petiole laterally flattened at base

Fruit: 2-valved

Habitat: Rocky Mountain forests

Habit: large tree

Leaves: 2-4 inches long if fascicles of 5

Reproductive structure: seed cone, stalked, up to 10 inches long, umbo unarmed

Bark: smooth on young trees, separated into deep fissures on older trees but remains smooth

Habitat: Rocky Mountain forests

Leaves: needles in fascicles of 2 but sometimes 1, dark green to yellow-green, often twisted

Reproductive structure: seed cones, often asymmetrical at base, subcyllindric to ovoid, apophysis flattened, becoming knoblike toward the base, umbo dorsal, ending in a long, recurved, and often deciduous prickle

Bark: thick and deeply furrowed, reddish brown to black

Habitat: Rocky Mountain forests

Leaves: 3-10 inches long, fascicles of 2-5

Twigs: stout, buds often covered in droplets of resin

Reproductive structure: seed cone, 2-6 inches long, ovoid to ellipsoidal, sessile, solitary or structured, apophysis transversely ridged and diamond-shaped, umbo dorsal and recurved, ends in a deciduous prickle

Habitat: Rocky Mountain forests

Habit: small tree

Leaves: 4-angled needles, pale blue-green and deciduous

Twigs: densely white wooly with numerous short shoots

Reproductive structure: erect seed cones, elliptical with exerted 3-toothed bracts

Habitat: timberline regions, Rocky Mountain forests

Habit: large tree

Leaves: flattened needles, nearly in 2 horizontal ranks

Reproductive structure: erect cyllindrical seed cone, purplish to nearly black, bracts shorter than pubescent scales

Habit: Rocky Mountain forests

Habit: large tree

Leaves: 4-sided needles, apex often blunt, somewhat appressed and tending to point forward on the twig

Twigs: pubescent with appressed buds

Reproductive structure: pendant seed cone, 1-3 iches long, ovoid-oblong, scales thin and papery

Habitat: Rocky Mountain forests

Habit: small, very long-lived tree

Leaves: needles in fascicles of 5, 3/4-1.5 inches long, bright green blue with small drops and scales of white resin

Reproductive structure: seed cone, subcyllindrical, rounded at base, umbo armed in a long, slender, incurved prickle

Habit: high elevations, Rocky Mountain forests

Habit: small tree with plume-like, drooping branches

Leaves: needles in fascicles of five, clustered toward branch ends, dark green, stout, rigid and not toothed

Reproductive structure: seed cone, 3-6 inches long, ovoid, scales thickened and slightly reflexed at apex

Habitat: high elevations, Rocky Mountain forests

Habit: small-medium tree

Leaves: needles 1-2 3/4 inches long, fascicles of five, clustered towards the ends

Bark: brownish white to creamy white on younger trees, smooth or superficially scaly at base and thin

Reproductive structure: seed cone, ovoid, purplish brown, serotinous, with thickened apophyses and terminally armed umbos

Habitat: Rocky Mountain forests