224 TREES 



and set seed. Close shut are the lips again, against any 

 other invasion, while these ovules mature. We shall find 

 them standing erect until autumn, but next season they 

 hang down with their added weight, and at the end of the 

 second summer the scales change from green to brown, 

 open and give their ripe winged seeds to the wind for dis- 

 tribution. Because the tree is biennial-fruited, it always 

 carries two sizes of cones. The large ones are one year 

 older than the small ones. Ripe cones are ^ve to ten 

 inches long, with thin, broad, unarmed scales, squarish at 

 the tips. 



The most hopeful phase of the white pine problem to-day 

 is the fact that new forests are coming up naturally where 

 the early lumbering deforested great tracts in the Eastern 

 states. Careful forestry improves upon nature's method, 

 and so the pines are being restored on land unfit for agri- 

 cultural crops. White pine is one of the most profitable 

 timber crops to plant at the present time. 



The Mountain Pine 



P. monticola, D. Don. 



The mountain pine is scattered through mountain forests 

 from the Columbia River Basin in British Columbia to 

 Vancouver Island, along the western slopes of the Rocky 

 Mountains to northern Montana and Idaho, and south 

 along the Sierra Nevada and Cascade ranges in Washing- 

 ton and Oregon, well into California. From the bottom 

 lands of streams, where it is most abundant and reaches a 

 height of one hundred to one hundred and fifty feet, and a 

 trunk diameter of five to eight feet, it climbs to elevations 

 of eight to ten thousand feet on the California Sierras. 



