ASPEN 



ASPEN. QUAKING ASP 



Pdpulus tremuloides. 

 Tremuloides refers to the fluttering habit of the leaves. 



Most widely distributed tree of North America. Prefers a rather 

 moist sandy soil and gravelly hillsides. Small, slender, rarely reach- 

 ing the height of fifty feet, but credited with one hundred feet in 

 northern Arizona at an elevation of 8,000 feet above the sea. Grows 

 rapidly and forms a narrow round-topped head. Roots large, vig- 

 orous and stoloniferous. 



Bark. On old trees near the base almost black ; higher on the 

 trunk and on young stems, pale greenish brown or yellow brown or 

 nearly white, often roughened with horizontal bands or wart-like ex- 

 crescences and marked below the branches with large, dark, lunate 

 scars. Branchlets at first red brown, and shining, turning finally to 

 a light gray, afterward becoming dark gray, for two or three years 

 much roughened by leaf-scars. The sweet inner bark in early spring 

 is used as food by the Indians of the north. 



Wood. Light brown, sapwood nearly white, soft, close-grained, 

 neither strong nor durable. Largely used in the manufacture of 

 paper ; and in the west for flooring and turnery. Burns freely when 

 green. Sp. gr., 0.4032 ; weight of cu. ft., 25.13 Ibs. 



Winter Buds. Leaf-buds slightly resinous, reddish brown, conical 

 acute, somewhat incurved, one-fourth of an inch long ; narrower 

 than the obtuse flower-buds. 



Leaves. Alternate, simple, one and a half to two inches long, 

 ovate or nearly round, slightly cordate or truncate at base, finely 

 serrate with glandular-tipped teeth, acute. Feather-veined, midrib 

 and primary veins conspicuous. They come out of the bud involute, 

 smooth, light green, shining, ciliate on 

 margins, when full grown are thin, dark 

 green, shining above, pale, dull, yellow 

 green beneath. In autumn they turn a 

 clear bright yellow. Tremulous. Pet- 

 ioles long, slender, and laterally com- 

 pressed. Stipules caducous. 



Flowers. April, borne in pendulous 

 aments one and a half to two and a half 

 inches long from buds formed the season A Staminate and \ ^^ Flower 

 before. The one-flowered scales are of Aspen Populus tremuloides . 

 deeply divided into three to five linear, enlarged, 

 acute lobes fringed with long, soft, gray 



hairs. Stamens from six to twelve, inserted on a disk which is 

 oblique, with entire margin. Ovary is conical ; style short, thick ; 

 stigmas two, divided into lobes. Ovary surrounded by broad 

 oblique disk, which is persistent. 



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