100 FOREST TREES OF THE PACIFIC SLOPE. 



seed ; they are borne nearly or quite at the ends of twigs. The male flowers — 

 scaly bodies bearing pollen only — grow from the bases of leaves farther back 

 from the end of the twig. Most characteristic of the pendulous cones of these 

 trees are their 3-pointed scale-like bracts, which protrude conspicuously from 

 among the cone-scales (fig. 30). No other cones of native conifers, with per- 

 sistent scales, have protruding bracts. The cones mature in one season, soon 

 afterward falling from the trees. Two winged seeds are borne under each 

 cone-scale. Their small size and large, light wings permit the wind to dis- 

 tribute them easily. 



They are trees (mainly one species) of the greatest commercial importance, 

 and furnish the finest and largest saw timber of any native trees, if not of any 

 trees in the world. The slightly resinous, pine-like wood is most widely adapted 

 for construction. Two native species of these trees are known. One is dis- 

 tributed more or less from the Rocky Mountain States to the Pacific coast, 

 while the other inhabits the mountains of southern California. 



Douglas Fir; Douglas Spruce. 

 Pseudotsuga taxifolia <* (Poir.) Britt. 



DISTINGUISHING CHARACTERISTICS. 



Excepting the great sequoias of California, Douglas fir is the most gigantic 

 tree of the Pacific forests. Under the best conditio is for growth it ordinarily 

 reaches 180 or 190 feet in height and from 3^ to fe >t in diameter. Trees over 

 200 feet high and 8 or 10 feet in diameter are to be t uind, but they are exceed- 

 ingly rare. Undej less favorable conditions, such as prevail outside of the 

 humid Pacific coast region, it commonly attains a height of from 75 to 110 

 feet and a diameter of from 18 to 30 inches; while in high, exposed situations 

 it is greatly stunted, often under 5 feet in height. The typical crown form of 

 young trees is a broad, sharp pyramid; the lower branches are straight or 

 drooping and the middle and higher ones trend upward, forming on the whole a 

 rather open head. All of the branches have numerous long, hanging side 

 branchlets, which are sometimes very long. In dense stands one-half or two- 

 thirds of the lower branches are shaded out by the time the trees are 10 or 15 

 inches in diameter. Under these conditions the crowns of middle-aged and old 

 trees lose much of their pyramidal form, and become rounded or flattened. 

 The massive trunks, clear of branches for 80 or 100 feet (in the Pacific region), 

 are straight, and with only a slight taper. The ashy brown bark of young 

 trees, often chalky in patches, is thin, smooth, and but little broken, except near 

 the ground, until the trees are 12 to 14 inches in diameter. Later, and in old 

 trees, the bark becomes from 5 to 10 inches thick at the base of the trunk, 

 although higher up it remains much thinner. Sometimes very old trees have 

 bark from 18 to 24 inches thick. It is dark brown on the outside and clear red- 

 brown within. It is often very rough, with deep, wide furrows and great 

 ridges, which are connected at intervals by narrower cross ridges. There is 

 great variation in the character and markings of the bark in dry and humid 

 regions, and also in exposed and protected situations. Trees in exposed, dry 



a Several authors maintain for this tree the name Pseudotsuga mucronata (Raf. ) 

 Sudworth, which the writer has shown to be lawfully antedated by P. taxifolia (Poir.) 

 Britt. For a full discussion of the basis of this decision, see Bull. 17, Div. For. p. 23. 



1808. 



