50 



FOREST TREES OF THE PACIFIC SLOPE. 



growing away from the coast and by the eastern representative of this species. 

 The thin bark results in extensive destruction of this tree by fire, which soon 

 .scorches the thickest of this bark so badly as to kill the trees. The Pacific 

 tree is 20 to 40 feet high and from 6 to 20 inches in diameter ; the trunk is 

 .short and thickly set with hugely developed branches, except in very dense 

 stands. In its eastern range the tree attains a height of from 50 to 100 feet, 

 and in close stands develops a smooth, clean trunk for from 30 to 60 feet ; from 

 12 to 24 inches is the usual diameter. Taller and larger trees occur. The 

 foliage of the coast tree is dark yellow-green, but away from the sea it becomes 

 distinctly a bright yellow-green, which is characteristic throughout the interior 

 Pacific and eastern range. The leaves (fig. 15), regularly 2 in a bundle, are 



Fig. 15. — Pinux contorta: a, seed with and without wing. 



from about 1 inch to nearly 3 inches long ; usually about 2 inches long. A 

 season's growth of leaves remains on the trees from six to eight years; long 

 persistence appears to belong more to young trees, on which leaves are retained 

 sometimes for nine years. The leaves of the Pacific form are only about one- 

 third as thick as those of the inland and eastern representative, which are nearly 

 an eighth of an inch wide. Cones (figs. 15, 16) ripen late in August and Septem- 

 ber. Very many trees open their cones in late fall and shed nearly all of their 

 seeds, while the cones of other trees in the same locality may remain closed for 

 a number of years. Open or closed they adhere to the branches for a great many 

 years, some of the closed ones finally opening and liberating their seed. The 



