FOREST TREES OF THE PACIFIC SLOPE. 



43 



later brownish. The foliage, borne in heavy brush-like clusters at the ends of 

 bare branches, is deep yellow-green. The leaves (fig. 13, a) occur 3 in a 

 bundle (rarely 4 and 5, chiefly on young saplings). They vary from about 4J 







Fig. 13. — Pinus ponder osa: a 3 leaf; 6, seed. 



to Hi inches. Each season's growth of leaves remains on the tree about three 

 years. The cones (fig. 13) mature early in August of the second season and 

 are variable also in size and color. The cones of some trees are bright grass- 

 green when mature, while those of other trees are dark purple; there is no 



