136 TREES OF NORTH AMERICA 



Distribution. Shores of Lake Champlain (Shelburne Point, Chittenden County), Ver- 

 mont; western New York; Island of the Delaware River above Easton, Northampton 

 County, Pennsylvania; Baltimore County, and Bare Hills, Maryland; northern banks of 



Fig. 130 



the Potomac River opposite Plummer's Island near Washington, D.C.; Artisia, Lowndes 

 County, and Starkville, Oktibbeha County, Mississippi; rare and local. 



Populus balsamifera var. virginiana Sarg. Cottonwood. 



Populus deltoidea Marsh, at least in part. 

 Populus nigra /3 virginiana Castiglioni. 



Leaves deltoid to ovate-deltoid, acuminate with entire points, truncate, slightly cordate 

 or occasionally abruptly cuneate at the entire base, crenately serrate above, with incurved 

 glandular teeth, fragrant with a balsamic odor, glabrous, thick and firm, light bright green 

 and lustrous, paler on the lower than on the upper surface, 3'-5' long and broad, with a stout 

 yellow midrib often tinged with red toward the base, raised and rounded on the upper 

 side, and conspicuous primary veins; petioles slender, pilose at first, soon glabrous, com- 

 pressed laterally, yellow often more or less tinged with red, 2'-3' long. Flowers and 

 Fruit: as on the type. 



A tree, sometimes 100 high, with a trunk occasionally 7-8 in diameter, divided often 

 20-30 above the ground into several massive limbs spreading gradually and becoming 

 pendulous toward the ends, and forming a graceful rather open head frequently 100 across, 

 or on young trees nearly erect above and spreading below almost at right angles with the 

 stem, and forming a symmetrical pyramidal head, and stout branchlets marked with long 

 pale lenticels, terete, or, especially on vigorous trees, becoming angled in their second year, 

 with thin more or less prominent wings extending downward from the two sides and from 

 the base of the large 3-lobed leaf-scars. Winter-buds very resinous, ovoid, acute, the lateral 

 much flattened, % long, with 6 or 7 light chestnut-brown lustrous scales. Bark thin, 

 smooth, light yellow tinged with green on young stems and branches, becoming on old 

 trunks l'-2' thick, ashy gray, and deeply divided into broad rounded ridges broken into 

 closely appressed scales. Wood dark brown, with thick nearly white sapwood, warping 

 badly in drying and difficult to season. 



