The Poplars 



Large-toothed Aspen (Populus grandidentaia, Michx.)— 

 Narrow, round-headed tree, 50 to 75 feet high, with stout, angular 

 branchlets, roughened by leaf scars. Bark dark brown and deeply 

 fissured between broad ridges on old trunks ; grey-green on limbs. 

 Twigs smooth, pubescent at first. Wood soft, weak, pale brown; 

 sap wood white. Buds ovate, pointed, scaly, waxed. Leaves 

 ovate to roundish, heart shaped at base, acute, with sparse, 

 irregular-rounded teeth; 3 to 4 inches long, 2 to 3 inches wide, 

 thick, green, with pale somewhat tomentose linings; petioles 

 slender, laterally flattened, 2 to 3 inches long. Flowers, April, 

 dioecious, in pendulous catkins, 2 to 3 inches long; staminate 

 red from anthers; pistillate green from spreading stigmas; bracts 

 deeply cleft. Fruits, hairy capsules, 2-valved, thin walled, slender, 

 crooked, filled with minute seeds, each with white, hairy float; 

 May. Preferred habitat, rich, sandy loam, on borders of streams. 

 Distrihution, Nova Scotia to Minnesota; south to New Jersey, and 

 on Alleghanies to North Carolina, Tennessee and Kentucky. 



The coarse, thick leaves with large, rounded teeth on the 

 margins, distinguished this great-toothed aspen from its dainty 

 cousin, the quaking asp, with which it is often associated in the 

 woods. In fact, the tree is coarser throughout, the branchlets 

 stout and the buds downy, so no one who is interested and ob- 

 servant will have any trouble to tell them apart. 



The Narrow-leaved Cottonwood (P. angustijolia, James) 

 has lanceolate leaves, more like a willow's than a poplar's. The 

 margins are finely saw toothed, the petioles short, and the texture 

 thin and firm. It is easy to see that the tree is a poplar, the 

 flattened petiole alone being a sufficient clue. The tree lines the 

 banks of mountain streams of the Rockies, 5,000 to 10,000 feet 

 in elevation. It grows from 40 to 60 feet high, a narrow pyramid 

 of slender limbs. 



The Lance-leaved Cottonwood {P . acummataj Rydb.), with 

 scarcely wider leaves than the preceding species, is a compact, 

 round-headed little tree that grows on stream borders and arid 

 foothills of the Rocky Mountains from British Columbia to 

 southern Nebraska and Colorado. Its distribution is not fully 

 ascertained. It is used for fuel and planted for shade in com- 

 munities within its natural range. 



The Mexican Cottonwood {P. Mexicana, Wesm.) grows, 

 a graceful, wide-spreading tree of medium size, along mountain 



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