290 



TREES OF NORTH AMERICA 



vided shaft to the height of 60-80 and separating into short spreading branches, 

 more commonly divided 30-40 from the ground into numerous upright limbs grad- 

 ually spreading and forming an inversely conical round-topped head of long graceful 

 branches, often 100 or rarely 150 in diameter, and slender branchlets frequently 

 fringing the trunk and its principal divisions, light green and coated at first with 

 soft pale pubescence, becoming in their first winter light reddish brown, glabrous or 

 sometimes puberulous and marked by scattered pale lenticels and by large elevated 

 semiorbicular leaf-scars showing the ends of three large equidistant fibro-vascular 

 bundles, later becoming dark reddish brown and finally ashy gray. Winter-buds 

 ovate, acute, slightly flattened, about |' long, with broadly ovate rounded light chest- 

 nut-brown glabrous scales, the inner bright green, ovate, acute, becoming on vigor- 

 ous shoots often nearly 1' long. Bark I'-l^' thick, ashy gray, divided by deep fis- 

 sures into broad ridges separating on the surface into thin appressed scales. "Wood 

 heavy, hard, strong, tough, difficult to split, coarse-grained, light brown, with thick 

 somewhat lighter colored sapwood; largely used for the hubs of wheels, saddle-trees, 

 in flooring and cooperage, and in boat and shipbuilding. 



Distribution. River bottom-lands, intervales, low rich hills, and the banks of 

 streams; southern Newfoundland to the northern shores of Lake Superior and the 

 eastern base of the Rocky Mountains, southward to Cape Canaveral and the shores 

 of Peace Creek, Florida, westward to the Black Hills of Dakota, western Nebraska, 

 western Kansas, the Indian Territory, and the valley of the Rio Concho, Texas; very 

 common northward, less abundant and of smaller size southward; abundant on the 

 banks of streams flowing through the midcontinental plateau. 



Largely planted as an ornamental and shade tree in the northern states, and rarely 

 in western and northern Europe. 



2. Ulmus Thomasi, Sarg. Rock Elm. Cork Elm. 



Leaves obovate to oblong-oval, rather abruptly narrowed at the apex into short 

 broad points, equally or somewhat unequally rounded, wedge-shaped or subcordate 



at the base and coarsely doubly serrate, when they unfold pilose on the upper sur- 

 face and covered on the lower with soft white hairs, at maturity 2'-2' long, '-!' 

 wide, thick and firm, smooth, dark green and lustrous above, paler and soft-pubes- 



