ASPEN 
ASPEN. QUAKING ASP 
Populus tremuloides. 
Lremuloides 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 lbs. 
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 turna 
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 4 caminate and a Pistillate Flower 
before. The one-flowered scales are of as SIT ib sintlnnice: 
sett =i is : spen, Populus tremuloides ; 
deeply divided into three to five linear,  gniarged. 
acute lobes fringed with long, soft, gray Z 
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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