50 HOUGH'S AMERICAN WOODS. 



223. TSUGA HETEROPHYLLA, SARG.* 

 WESTERN HEMLOCK. 



Ger., Westliclie Tanne ; Fr., Peruclie occidental' Sp., Abeto 



occidental. 



SPECIFIC CHARACTERS : Leaves, linear, flat, from^-f in. long, rather less than a 

 line in width, rounded at apex, abruptly tapering at the base to a slender petiole, 

 entire or spinulose-serrulate towards the tip, grooved and lustrous dark green 

 above and with white bands of stomata beneath; branchlets pale brown, very 

 slender and rough with the persistent bases of the petioles ; leaf-buds small, 

 about fa in. long, bright brown, puberulous. Flowers staminate yellow, about 

 | in. in length and rather shorter than the slender stipe, pollen grains discoidal : 

 pistillate flowers purple, about ^ in. long and terminating the small branchlets. 

 Fruit cones sessile, oblong-cylindrical when closed, f-1 in. in length and with 

 thin scales slightly puberulous outside and light reddish brown at maturity ; 

 branchlets small, rounded or acute at apex, dark purple, puberulous ; seeds 

 about in. long, with narrow wing two or three times as long and occasional oil 

 vesicles ; cotyledons f . 



The Western Hemlock is the largest representative of its genus, 

 sometimes attaining the height of 200 ft. (60 m.), and a diameter of 

 trunk of 8 or 10 ft. (3 m.). It forms a rather narrow pyramidal top 

 of gracefully sweeping branches and slender drooping branchlets. 

 The bark is very similar to that of the eastern species, being on old 

 trunks of a chocolate-brown color, deeply fissured into prominent 

 longitudinal and obliquely connecting ridges and exfoliating in thick - 

 ish irregular scales. 



HABITAT. From southeastern Alaska, where it surpasses all other 

 forest trees in size, southward nearly to San Francisco and eastward 

 to the western slopes of the continental divide. It is most abundant 

 and luxurious in the humid region along the coast from sea-level up 

 to an altitude of about 2,000 ft., being most abundant in western 

 Washington, Oregon and British Columbia. Farther inland it ascends 

 to an altitude of 6-8,000 ft. on favorable slopes. 



PHYSICAL PROPERTIES. Wood light, rather hard and tough, close- 

 grained, susceptible of a good polish, of a pale, yellowish -brown color 

 with lighter sap-wood. Specific Gravity, 0.5182; Percentage of A*h, 

 0.42; Relative Approximate Fuel Value, 0.5160; Coefficient of Elas- 

 ticity, 137483 ; Modulus of Rupture, 909 ; Resistance to Longitudi- 

 nal Pressure, 547; Resistance to Indentation, 101; Weight of a 

 Cubic Foot in Pounds, 32.39. 



USES. Lumber made from this tree is more easily worked, stronger 

 and more durable than that furnished by our eastern Hemlock, and it 

 is used to considerable extent in house-building and for general con- 



* Tsuga mertaisiana, authors, not Carr. 



