4:2 HOUGH'S AMERICAN WOODS. 



glabrous, and falling away before the ripening of the fruit; stamens 20-60, inserted 

 on a broad glabrous disk; ovary subglobose, hoary tomentose, and with three 

 broadly dilated and lobed nearly sessile stigmas and inclosed at base with cup- 

 shaped glabrous disk. Fruit, capsules nearly sessile, subglobose, pubescent, about 

 3 lines in diameter, 3-valved; seed about 1 line long, light brown, and furnished 

 with a tuft of white hairs. 



The specific name, trichocarpa, is from Greek roots indicating hairy fruit, and 

 referring here to the hairy capsules. 



One of the largest of the genus, this Cottonwood sometimes attains 

 the height of nearly 200 ft. (60 m.) with sturdy trunk 6 or 8 ft. 

 (2 m.) in diameter. When growing apart from other trees its trunk 

 divides into few large branches which ramify into a broad open top. 

 The bark of the old trunk is of a grayish-brown color, furrowed 

 lengthwise by deep clefts which enter nearly to its cambium layer and 

 between which the long, rounded, firm ridges may become 2 in. or 

 more in thickness. 



HABITAT. The Populus trichocarpa ranges from Alaska south- 

 ward along the banks of streams and in low-lands throughout all the 

 coast region to northern California, and in these localities attains its 

 greatest dimensions, being here the largest of the broad-leaved trees. 

 It is found as a smaller tree to the southward among the mountains of 

 California ascending the caTions of the Sierra Nevadas to an altitude 

 of about 6,000 ft. but reaching its southernmost limit in the San Ber- 

 nardino mountains. It is also found on the larger islands lying off 

 the coast of California. 



PHYSICAL PROPERTIES. Wood soft, light, not strong, easily worked, 

 excepting for the tendency of the heart- wood to dull tools a trait 

 common to most of the representatives of the genus. It is of a light- 

 brown color, mottled or streaked with darker, and the gap-wood is 

 nearly white. Specific Gravity, 0.3814; Percentage of Ash, 1.27; 

 Relative Approximate fuel Value, 0.3766 ; Coefficient of Elasticity 

 111694; Modulus of Rupture, 665; Resistance to Longitudinal 

 Pressure, 390; Resistance to Indentation, 63; Weight of a Culic 

 Foot in Pounds, 23.77. 



USES. In Washington and Oregon this wood is used quite exten- 

 sively in the manufacture of bowls and general wooden ware, the 

 staves of sugar barrels, etc., and it is said that the Indians of British 

 Columbia use it for making their canoes, and those of northern Cali- 

 fornia and Oregon formerly used the tough roots in the manufacture 

 of hats and baskets. 



MEDICINAL PROPERTIES. The peculiar exudation of the leaf -buds 

 of this species, though not specifically mentioned in medicine, doubt- 

 less possesses the same properties that are common to other representa- 



