6 KEY TO THE SPECIES 



3. Pinus scopulOTum (Engelm.) Lemmon (Rock Pine). A large tree, 25-40 

 m. high, 1-2 m. in diameter ; leaves 12-16 cm. long, mostly 3 in each bundle (rarely- 

 only 2), in dense brush-like bunches at the ends of the branches ; cone 7-10 cm. 

 long ; scales thickened at the tip, which bears a sharp, recurved prickle. 



• ♦ ♦ Leaves 5 in each bundle. 



4. Pinus flexilis James (Limber Pine). A tree of wind-swept hills and sum- 

 mits, scattering, often much distorted ; branches very flexible ; leaves 4-7 cm. 

 long ; cones light colored, 8-10 em. long, egg-shaped ; scales with broad, slightly 

 thickened tips, widely spreading when mature. 



3. PICEA (Spruce) 



Spire-shaped trees, often tall and slender ; leaves spirally arranged, jointed 

 near the base, falling when dry and leaving the branchlets rough with the project- 

 ing bases ; cones pendulous, oblong, of numerous scales bearing two ovules. 



* Branchlets pubescent ; leaves abruptly sharp-pointed. 



1. Picea iEngelmanni Engelm. (Engelmann Spruce). A large tree of the 

 higher mountains, forming dense forests ; on alpine summits depressed and 

 matted ; leaves keeled, 2-3 cm. long ; cones solitary, oblong, about B cm. long. 



* Branchlets smooth and shining ; leaves needle-pointed. 



2. Picea Parryana (Andre.) Parry (Blue Spruce). A small, conical tree 

 with soft wood, and smooth bark when young ; leaves slender, sharply 4-angled, 

 usually bluish green ; cones narrowly oblong, 5-10 cm. long, drooping, generally in 

 clusters, and numerously crowded at the summit of the tree. This tree prefers 

 moist situations. It is extensively used for ornamental planting, tor which its 

 beautiful color and handsome outline admirably flt it. As the chosen '* State 

 Tree " of Colorado it is of interest. 



3. PSEUDOTSUGA (False Hemlock-spruce) 



A large, stately tree, occurring in the mountains at middle elevations, on 

 moist slopes and plateaus ; leaves with a short petiole, twisting on the base so as, 

 to appear comb-like on the branches, which are smooth when the leaves have 

 fallen and marked only by oval scars. 



1. Pseudotsnga taxifolia (Lam.) Britt, (Douglas Spruce). Often 35-50 m. 

 high ; bark thick and fnrrowed ; leaves flattened, blunt pointed, whitish below, 2 

 cm. or more in length ; cones oval, 7-9 cm. long, perfectly characterized by the 

 fringe-like, somewhat reflexed, 3-pointed bracts which project from among the 

 scales of the cone. 



4. JUNIPERUS (Juniper) 



• Leaves short, blunt and scale-like (except in seedlings). 



1. Juniperus scopulorum Sargent (KocKV Mountain Juniper). Becoming 

 a low, round-topped tree with thick trunk, or sometimes freely branched from 

 the base (rarely; Jn very exposed situations, a mere shrub); leaves in pairs, very 

 short, nearly clothing the branchlets ; berries very numerous, not maturing till 

 the second season, light green when young, when mature blue with whitish bloom. 



« « Leaves awl-shaped, prickly-pointed, 10-15 mm. long. 



