6 



TREES OF NORTH AMERICA 



largely manufactured into lumber and used for the interior finish of buildings, woodwork, 

 and shingles. A sweet sugar-like substance exudes from wounds made in the heart wood. 



Distribution. Mountain slopes and the sides of ravines and canons; western Oregon 

 from the valley of the north branch of the Santiam River southward on the Cascade and 

 coast ranges; California along the northern and coast ranges to Sonoma County; along 

 the western slopes of the Sierra Nevada, where it grows to its greatest size at elevations 

 between 3000 and 7000; reappearing on the Santa Lucia Mountains of the coast ranges; 

 and on the high mountains in the southwestern part of the state from Santa Barbara 

 County southward usually at elevations of 5000-7000 above the sea; and on the San 

 Pedro Martir Mountains in Lower California. 



Occasionally planted as an ornamental tree in western Europe and in the eastern states, 

 the Sugar Pine has grown slowly in cultivation and shows little promise of attaining the 

 large size and great beauty which distinguish it in its native forests. 



4. Pinus flexilis James. Rocky Mountain White Pine. 

 Pinus strobiformis Sarg., not Engelm. 



Leaves stout, rigid, dark green, marked on all sides by 1-4 rows of stomata, I%'-3' long, 

 deciduous in their fifth and sixth years. Flowers: male reddish; female clustered, bright 

 red-purple. Fruit subcylindric, horizontal or slightly declining, green or rarely purple at 

 maturity, 3'-10' long, with narrow and more or less reflexed scales opening at maturity; 

 seeds compressed, |'-f ' long, dark red-brown mottled with black, with a thick shell pro- 



duced into a narrow margin, their wings 

 about jV wide, generally persistent on 

 the scale after the seed falls. 



A tree, usually 40-50, occasionally 80 

 high, with a short trunk 2-5 in diameter, 

 stout long-persistent branches ultimately 

 forming a low wide round-topped head, 

 and stout branchlets orange-green and 

 covered at first with soft fine pubescence, 

 usually soon glabrous and darker colored; 

 at high elevations often a low spreading 

 shrub. Bark of young stems and branches 

 thin, smooth, light gray or silvery white, 

 becoming on old trunks l'-2' thick, dark 

 brown or nearly black, and divided by 

 deep fissures into broad ridges broken into 

 nearly square plates covered by small 

 closely appressed scales. Wood light, 

 soft, close-grained, pale clear yellow, turning red with exposure; occasionally manufactured 

 into lumber. 



Distribution. Eastern slope of the Rocky Mountains from Alberta to western Texas 

 and westward on mountain ranges at elevations of 5000 to 12,000 to Montana, and south- 

 ern California, reaching the western slopes of the Sierra Nevada at the head of King's 

 River near the summit of San Gorgonio Mountain and in Snow Canon, San Bernardino 

 Range; usually scattered singly or in small groves; forming open forests on the eastern foot- 

 hills of the Rocky Mountains of Montana and on the ranges of central Nevada; attaining 

 its largest size on those of northern New Mexico and Arizona. 



5. Pinus albicaulis Engelm. White Pine. 



Leaves stout, rigid, slightly incurved, dark green, marked by 1-3 rows of dorsal stomata, 

 clustered at the ends of the branches, 1|'-2|' long, persistent for from five to eight 

 years. Flowers opening in July, scarlet. Fruit ripening in August, oval or subglobose, hori- 



Fig. 4 



