97 



; 



LARGE-TOOTHED ASPEN. 

 Populus grandidentata, Michaux. 



FORM — Usually a small tree 30-40 ft. high but may reach a height of 70 ft. with a diameter 

 of 2 feet. More frequent and larger in this State than the American Aspen. Trunk continuous 

 and tapering. Crown often irregular, due to the absence of branches which have been broken 

 off on account of theii brittleness. Branches usually less ascending than those of the American 

 Aspen. 



BARK — Near the base of old trunks black, very rough, thick, hard, does not heal over 

 branch wounds rapidly. Large smooth surfaces found on flat ridges between fissures. Smaller 

 branches similUi.' to those of the American Aspen but with a more pronounced yellow color. 

 See Fig. 95. 



TWIGS — Rather stout, reddish to yellowish-brown, round, often covered with a coating of pale, 

 woolly, crusty down which occasionally peels off in small flakes. 



BUDS — Alternate, ovate to conical, pointed, dusty, dull, usually divergent, covered by 6-7 

 light chestnut-brown scales which are often coated with a dusty flour-like mat of a pale, woolly 

 substance. Basa.' scale of lateral buds on outside. 



LEAVES — Alternate, simple, broadly-ovate, wedge-shaped to cordate at base, acute to 

 acuminate at apex, coarsely dentate on margin, 3-4 inches long, dark green above, pale green 

 below. Leaf-stalks laterally flattened. 



LEAF-SCARS — Same as leaf-scars of American Aspen, page 96. Stipule-scars are less distinct. 



FLOWEiRS — See "Flowers" under American Aspen, page 96. 



FRUIT — An ament bearing scattered, light, green, 2-valved capsules which contain minute 

 dark brown seeds surrounded by a mat of long white hairs. 



WOOD — Same as American Aspen, page 96. 



DISTINGUISHING CHARACTERISTICS— The Large-toothed Aspen, also known as Popple 

 and Poplar, may be distinguished by its coarsely wavy-toothed leaves, larger than those of the 

 American Aspen which it closely resembles. See "Distinguishing Characteristics" under the 

 latter. It does not have the resinous buds, nor the ridged bark on the twigs, nor the deltoid 

 leaves so characteristic of the Cottonwood. The bark is often covered with oyster-shell-like 

 bodies whicn are the armored portion of the oyster-shell scale. Many small trees are killed by 

 this scale. 



RANGE — \ova Scotia and Ontario south to Pennsylvania, along mountains to North Carolina 

 and west to Minnesota 



DISTRIBUTION IN PENNSYLVANIA— Rather common throughout the State especially on 

 lumbered and burnt-over areas, in abandoned flelds, and on charcoal hearths. Usually found 

 in mixture, but occasionally in small pure stands. 



HABITAT — Prefers rather rich moist soil, but is also found on dry gravelly soil. Usually 

 large on moist situations and smaller, often scrubby, on very dry situations. Frequent asso- 

 ciates are Birch, Bird Cherry, Shad Bush, and Scrub Oak. 



IMPORTANCE OF THE SPECIES— The Large-toothed Aspen is of no commercial Importance 

 in this State. It is of value in our lumbered areas because it covers the soil rapidly, acts 

 a.s a soil-conserver, and often as a soil-improver. It may also act as a temporary shelter for 

 more valuable species while they are young and establishing themselves. It also aids in shading 

 out our most aggressive forest weed — Scrub Oak. 



7 



