American Aspen 



179 



ways and about as long as the blades. At flowering time in March or April the 

 catkins are 5 to 8 cm. long, and not very dense; the pistillate flowers are short- 

 stalked, the disk small, the usually 3 stigmas much dilated. In ripening, the pis- 

 tillate catkins become 12 cm. long or more, the papillose capsules i to 1.5 cm. 

 long, and longer than their stalks. 



The. tree is much planted for shade and ornament; its wood much resembles 

 that of its eastern relative, but is lighter, its specific gravity being about 0.34. 



16. LARGE-TOOTHED ASPEN — Populus grandidentata Michaux 



A forest tree, attaining a maximum height of about 25 meters, with a trunk 

 sometimes 6 to 7 meters thick. It prefers rich soil, and ranges from Nova Scotia 

 to Delaware, in and along the mountams 

 south to North Carolina, westward to Ontario, 

 Minnesota, lUinois, and Tennessee. 



The bark is thin, smooth, and light greenish 

 brown, except at and near the bases of old 

 trunks where it is much thicker, fissured and 

 dark brown. The stout young twigs are quite 

 velvety, becoming smooth, reddish brown, and 

 shining. The buds are finely hairy, 5 or 6 

 mm. long, and pointed. The leaves are ovate, 

 6 to 12 cm. long, or those of young trees very 

 much larger (sometimes 3 dm. long); when 

 young they are densely white-velvety on the 

 under side, becoming smooth or nearly so 

 when old, or those of young shoots persistently 

 velvety beneath; they are pointed at the apex, 

 and rounded or narrowed at the base, rarely somewhat heart-shaped, coarsely and 

 irregularly toothed, or those of young shoots finely toothed; the upper surface is 

 dark green and dull; the leaf-stalks are laterally flattened, 2.5 to 7 cm. long, the 

 stipules linear, 2 cm. long or less. The catkins appear in March or April, and 

 are 10 cm. long or less at flowering time, the pistillate ones much elongated in 

 fruit; the scales are long-hairy, irregularly lobed above the middle; the staminate 

 flowers have 6 to 12 stamens; the stigma-lobes of the pistillate flowers are linear. 

 The ripe capsule is conic, about 6 mm. long and papillose. 



The foliage turns bright yellow in autumn. The wood is weak and soft, is 

 largely used for paper-pulp, and to a small extent for woodenware; it is light brown 

 with a specific gravity of about 0.46. 



Fig. 137. — Large-toothed Aspen. 



17. AMERICAN ASPEN — Populus tremuloides Michaux 



The American aspen is widely distributed, ranging from Newfoundland across 

 British America to Alaska, south to southern New York, Pennsylvania, Kentucky, 



