THE SPECIES. 



51 



On the ends of the ultimate twigs the small flowers are borne, each 

 kind consisting of a few pairs of scales, each pair at right angles to 

 the one above or below. The cones, which are often produced in great 

 numbers,- are half an inch or less in length, each of the fertile scales 

 producing one or more seeds. These seeds, unlike those of the preced- 

 ing species, are surrounded by the wing; they are oval in form, a 

 quarter of an inch or less in length. The trunk of the tree is usually 

 much folded at the base, with buttress-like roots. The bark is 1 inch, 

 more or less, in thickness, light gray, and divided by long furrows ; 

 it is strongly fibrous, separating, 

 upon proper manipulation, into 

 long, ribbonlike strips. 



The western arbor vitce (Thuya 

 plicata) is found from southern 

 Alaska to northern California 

 along the coast, in the Cascades 

 through Washington and Oregon, 

 and in the Rocky Mountains to 

 Montana and Idaho. It reaches 

 its best development in the deep, 

 moist soils of the lowlands along 

 the coast of Washington and Brit- 

 ish Columbia, where large speci- 

 mens are found 10 to 15 feet in di- 

 ameter, some of them with a height 

 of 200 feet or more. The lumber of 

 this tree is of high value, being 

 light, soft, easily worked, and very 



durable. Especially is the latter true of older trees, the growth 

 of which has been very slow as they approached maturity, resulting 

 in a fine and uniform grain. One may often find in the forests of the 

 coast region prostrate trunks in sound condition which have lain so 

 long that other forest trees to a diameter of several feet have grown 

 on top of them, with huge roots reaching down on either side. This 

 timber is used almost exclusively, in the Xorthwest, for telegraph 

 poles and shingles; the lumber is useful also for many other pur- 

 poses. The tree is capable of enduring deep shade, and grows often 

 in mixtures with other species. In Montana the arbor vitse is found 

 only west of the Divide, where it attains a diameter of several feet 

 in the river bottoms and deep canyons under conditions of perennial 

 moisture. 



This tree is recognized by its flat sprays of small twigs that form 

 a compact system. The twigs are distinctly flat, and the leaves in 

 pairs, forming four ranks of closely overlapping scales. The cones 

 are three-eighths or half an inch long, borne on the ends of the 



FM;. '.}-. -Arbor Vitft?. A, Twig and cone; 

 scale-like leaves ; B, scale ; C, seed. 



