PINACEAE 



Western Redcedar. Giant Arborvitae 

 Thuja plicata Donn 



HABIT. A large tree, 1 50-200 feet high and 4-8 feet in diam- 

 eter (max. 250 by 16 feet); tapering, fluted trunk; irregular 

 crown of horizontal or drooping branches. 



LEAVES. Small, scalelike; persistent 2-5 years; decussate 

 the facial leaves flattened, grooved; the lateral leaves rounded 

 or keeled; lustrous dark yellow-green. 



FLOWERS. Monoecious; terminal; dark brown; male with 

 3-6 pairs of decussate stamens; female 8-12 scaled. 



FRUIT. Leathery or sub-woody erect cones; Yi inch long; 

 ovoid-oblong; maturing in one season; scales 8-12 (only 6 being 

 fertile), thin, spine-tipped. Seed: Vq inch long, brown, with lateral 

 wings each about as wide as seed. 



TWIGS. Slender; flattened; leaf-covered in long drooping 

 sprays. Winter buds: minute, naked, inconspicuous. 



BARK. Thin (]/2-l inch); fibrous; narrow interlacing ridges; 

 cinnamon-red to gray-brown on old trunks. 



WOOD. Widely used where durability rather than strength 

 is required; sapwood white; heartwood reddish, soft, fragrant; 

 shingles, siding, interior trim, boats, poles, etc. 



SILVICAL CHARACTERS. Tolerant; growth rather rapid; 

 trees over 1,000 years old reported; reproduction generally 

 plentiful; shallow, wide-spreading root system; fire and pecky 

 heart rot cause serious damage. 



HABITAT. Transition and Canadian zones; altitudinal 

 range 2,000-7,000 feet in Rocky Mountains; on rich soils with 

 abundant moisture; in mixed coniferous stands. 



* * * 



Northern White-cedar. Eastern Arborvitae 

 Thuja occidentalis L. 



Aside from its eastern distribution, this species diff'ers from 

 Thuja plicata by only minor characters, the cones having but 

 4 fertile scales and the leaves being dull green and usually gland- 

 ular-pitted. This small tree grows on a variety of sites and is 

 typical of swampy areas. It is not important, although used to 

 some extent for posts and poles. The oriental arborvitae, T. 

 orientalis L., is widely planted and perhaps naturalized. It is 

 easily distinguished from the native species by the vertical dis- 

 position of the leaf sprays, the thick cone scales, and the wingless 

 seed. 



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