Resinous trees and shrubs mostly with evergreen, narrow, entire or scale-like leaves; the pollen sacks and ovules borne in separate spikes; fruit a cone with numerous, several or few, woody, papery or fleshy scales, sometimes berry-like; seed wingless or winged.

A tree 20 or 30 feet high generally with a short trunk 2—4 feet in diameter, stout, very flexible branches, often standing nearly erect and forming an open irregular broad head; often a low shrub and nearly prostrate at high altitudes; bark thin with creamy-white plate-like scales; leaves stout, rigid, slightly incurved, clustered at the ends of the branches 1½—2½ inches long; cones oval or subglobose horizontal, sessile, dark purple, 1½—3 inches long with thickened acute scales.

On alpine slopes and exposed ridges from 5000 feet elevation upward, occurring occasionally in the Rockies, but frequent throughout the Selkirks at or near the timber line.

A tree 40—80 feet high with a trunk 1—3 feet in diameter, slender, strict; branches frequently persistent nearly to the base of the stem, somewhat pendulous below, ascending near the top of the tree, forming a pyramidal spire-topped head; bark thin, close, light orange-brown with appressed scales; leaves 2 in a bundle, yellowish-green, 1—3 inches long, stout; cones yellowish-brown and shining oval to sub-cylindric oblique at the base, often clustered ¾—2 inches long, with slightly concave scales with slender deciduous prickles.

The most abundant tree at the lower altitudes throughout the Rockies, frequently covering vast tracts, and rising on the mountain sides to 6000 feet or occasionally higher.

A tree usually 40—50 feet high with a diameter of 18—20 inches and remote, elongated, tough, persistent, nearly black branches, with prominent winter buds with conspicuous long white matted hairs fringing the margins of their scales and often nearly concealing the buds; bark on the old trunks ½ to ¾ of an inch thick, pale gray, divided into shallow irregular plates; leaves many in a cluster, 4-angled, slender, blue-green 1—1½ inches long; young cones showy with dark red or yellow-green scales and dark purple bracts; when mature, ovate 1½—2 inches long with reddish-purple scales and long tipped dark purple bracts.

An alpine tree occurring with more or less frequency throughout the Rockies from Banff to Field, from 6000 to 8000 feet elevation, at or near the tree limit, often much stunted and almost shrub-like; very abundant on the mountains in the region about Lake Louise.

A tree usually 40—100 feet high with a trunk 1—5 feet in diameter, short crowded tough branches, usually slightly pendulous near the base and forming dense spire-like slender heads; bark rough on the older trees, with thick, appressed, cinnamon-red scales; leaves pale blue-green flat, 1—1¾ inches long on the lower branches, rounded or notched at the apex; on the upper branches thickened, not more than ½ an inch long, flattened and closely appressed with long rigid points; cones, oblong-cylindric, rounded, truncate or depressed at the narrowed apex, dark purple and soft-hairy, 1½—4 inches long with scales gradually narrowed from the broad rounded apex to the base, about 3 times as long as the bracts.

This tree the Balsam of the region is found throughout on the higher mountain slopes and summits, frequently forming the timber line in which case it is shrub-like and stunted.

A magnificent tree 80—100 feet high, with a trunk 2—3 feet in diameter, or frequently larger, with slender crowded branches and long pendulous lateral ones forming, while the tree is young, an open pyramid, soon deciduous from the trees crowded in the forest and leaving the bare trunk naked for ⅔ of its height and surmounted by a comparatively small, narrow head; bark on the young trees, smooth, dark gray-brown and lustrous, on the old trunks several inches thick, divided into oblong plates broken into irregularly connected ridges; leaves crowded, yellowish-green, straight or slightly curved, narrow, ¾—1¼ inches long, obtuse or acute at the apex; cones pendent on long stout stems, 2—4¼ inches long, with thin slightly concave scales; bracts often extending half an inch beyond the scales.

Throughout the Rockies in the lower wooded valleys, the handsomest tree of this section especially when young, now rather rare in the mature state along the line of the railway, but may be so seen to perfection in the Yoho and some of the other outlying valleys.

A tree frequently 200 feet high, with a trunk 6—10 feet in diameter, with short slender usually pendulous branches forming a narrow pyramidal head; bark orange-brown, thin when young, an inch or more thick on mature trees and divided into broad flat ridges; leaves flat, dark green and lustrous on the upper surface, marked below by broad white bands; cones sessile, oblong or oval, ¾—1 inch long with few yellowish-brown oblong scales abruptly contracted at the middle and purplish toward the base.

Abundant throughout the Selkirks.

Tree usually 70—100 feet high with a tapering trunk 2—5 feet in diameter and gracefully pendent slender branches and drooping lateral ones; bark grayish and scaly, on mature trees 1—1½ inches thick divided into rounded ridges with closely appressed cinnamon scales; leaves more or less in clusters, standing out all over the sides of the branches, rounded, light bluish-green or in some pale blue ½—1 inch long; cones sessile, cylindric, oblong, narrowed toward the blunt apex and somewhat toward the base, pendulous, 1—3 inches long, with thin scales usually as broad as long, with slightly thickened or erose margins, purplish-brown, 4 times as long as the sharp, purple bract.

On the slopes and exposed ridges through the Selkirks, a most attractive tree.

A tree 30—60 feet high, slender, strict; twigs smooth and shining or occasionally glandular, hairy, but never glaucous, yellowish-brown when young becoming darker with age, leaf bases long and standing out at right angles from the stem; leaves pale blue or blue-green, ½—1 inch long, nearly straight or curved, acute or with a rigid tip, 4-sided; cones ovate or oblong, bright crimson when young, at maturity 1—1½ inches long and nearly as broad when expanded, scales stiff and rigid, broadly rounded at the apex, entire, broader than long, cinnamon brown with a chestnut edging; bract very small with a sharply angular tip.

The common spruce in the lower valleys and river bottoms throughout the Rockies.

A tree often 150 feet high but usually much lower, with a trunk reaching 4—5 feet in diameter; spreading branches, produced in regular whorls and forming a narrow compact pyramidal head, and gracefully hanging short lateral branches; bark when mature reddish-brown and broken into thin scales; leaves soft and flexible, slender or slightly incurved, stouter on the fertile branches, ½—1⅛ inches long, glaucous when young, becoming dark blue-green; cones oblong-cylindric, 1—2 inches long, lustrous, light chestnut brown with thin flexible wedge-shaped scales, with erosedentate margins.

On the higher mountain slopes in the Rockies, but much lower in the valleys of the Selkirks, where it grows to a great size.

A depressed rigid shrub, with many slender, decumbent stems, curving upward and forming a circular mass frequently 10 feet in diameter and 18 inches high; bark reddish-brown; leaves numerous ⅓—½ an inch long, awl-shaped, rigid, spreading nearly at right angles to the branches, linear-lanceolate, acute, and tipped with sharp, slender points; channelled and whitened above, lustrous green beneath; berry-like cones, blue and glaucous, subglobose or oblong about ¼ of an inch in diameter.

On dry hills and stony slopes throughout the region.

A depressed, creeping shrub seldom more than a foot high, with spreading branches; bark grayish-brown; leaves scale-like, appressed, 4-ranked, acute, with a short spiny point; berry-like cones, light blue and glaucous, a third of an inch in diameter.

On dry stony ground and slopes throughout the Rockies.

A tree frequently 200 feet high with a broad, gradually tapering buttressed base sometimes 15 feet in diameter; branches short, horizontal, usually pendulous at the ends, bright yellow-green during the first year, becoming reddish-brown and lustrous; bark thin, cinnamon-red, divided into broad rounded ridges by shallow fissures; leaves ovate, long pointed, ¼ of an inch long or less; cones purplish-brown, much reflexed, clustered at the ends of the branches, ½ inch long with 6 oblong thin leathery scales with thickened spine-bearing tips.

Occasionally met with in the lower valleys on the western slope of the Rockies; becoming an immense forest tree in the moist valleys of the Selkirks where it forms a striking feature of the landscape.