ASPEN 



ASPEN. QUAKING ASP 



rSpiiliis trentuloid^s, 

 fi-LimiloidiS refers to the fluttering habit of the leaves. 



ISIost 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 tuo 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. 



Whiter Buds. — Leaf-buds slightly resinous, reddish brown, conical 

 acute, somewhat incurved, onc-lourth 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 teetlr, 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 ^>s.u 

 green, shining above, pale, dull, yellow , =Mi™ 

 green beneath. In autumn they turn a ~%^,^^M 

 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 

 before. The one-flowered scales are 

 deeply divided into three to five linear, 

 acute lobes fringed with long, soft, gray 

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

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

 stigmas two, divided into lobes. Ovary surrounded by broad 

 oblique disk, which is persistent. 



413 



A Staminate and a Pistillate Flower 

 of Aspen, Populus t7-e}nuloidcs ; 

 enlarged. 



