A tree, often 60°—70° high, with a trunk occasionally 2° in diameter, slender rather rigid branches forming a narrow round-topped head, and stout branchlets marked by scattered oblong orange-colored lenticels, coated when they first appear with thick hoary deciduous tomentum, becoming during their first year dark red-brown or dark orange-colored, glabrous, lustrous, or covered with a delicate gray pubescence, and in their second year dark gray sometimes slightly tinged with green and much roughened by the elevated 3-lobed leaf-scars; generally smaller, and usually not more than 30°—40° tall. Winter-buds terete, broadly ovoid, acute, with light bright chestnut-brown scales, pubescent during the winter especially on their thin scarious margins, about ⅛′ long and not more than half the size of the flower-buds. Bark thin, smooth, light gray tinged with green, becoming near the base of old trunks ¾′—1′ thick, dark brown tinged with red, irregularly fissured and divided into broad flat ridges roughened on the surface by small thick closely appressed scales. Wood light brown, with thin nearly white sapwood of 20—30 layers of annual growth.
Distribution. Rich moist sandy soil near the borders of swamps and streams; Nova Scotia, through New Brunswick, southern Quebec and Ontario to northern Minnesota, southward through the northern states to Pennsylvania, northern Ohio, and eastern (Muscatine County) and central Iowa, and westward to central Kentucky and Tennessee; passing into the var. meridionalis Tidestrom with broad-ovate acuminate leaves with more numerous teeth, often 4′—5′ long and 3′ wide; the common form in Maryland, northern Delaware, the piedmont region of Virginia and North Carolina, southern Ohio, and southern Indiana and Illinois; rare northward to northern New England.
3. [Populus heterophylla] L. Swamp Cottonwood. Black Cottonwood.
Leaves broadly ovate, gradually narrowed and acute, short-pointed or rounded at apex, slightly cordate or truncate or rounded at the wide base, usually furnished with a narrow deep sinus, finely or coarsely crenately serrate with incurved glandular teeth, covered as they unfold with thick hoary deciduous tomentum, becoming thin and firm in texture, dark deep green above, pale and glabrous below, with a stout yellow midrib, forked veins and conspicuous reticulate veinlets, 4′—7′ long, 3′—6′ wide; petioles slender terete tomentose or nearly glabrous 2½′—3½′ in length. Flowers: staminate aments broad, densely flowered, 1′ long, erect when the flowers first open, becoming pendulous and 2′—2½′ long; scales narrowly oblong-obovate, brown, scarious and glabrous below, divided into numerous elongated filiform light red-brown lobes; disk oblique, slightly concave; stamens 12—20, with slender filaments about as long as the large dark red anthers; pistillate aments slender, pendulous, few-flowered, 1′—2′ long, becoming erect and 4′—6′ long before maturing, their scales concave and infolding the flowers, linear-obovate, brown and scarious, laterally lobed, fimbriate above the middle, caducous; disk thin, irregularly divided in numerous triangular acute teeth, long-stalked; ovary ovoid, terete or obtusely 3-angled, with a short stout elongated style and 2 or 3 much-thickened dilated 2 or 3-lobed stigmas. Fruit on elongated pedicels, ripening when the leaves are about one third grown, ovoid, acute, dark red-brown, rather thick-walled, 2 or 3-valved, about ½′ long; seeds obovoid, minute, dark red-brown.
A tree, 80°—90° high, with a tall trunk 2°—3° in diameter, short rather slender branches forming a comparatively narrow round-topped head, and stout branchlets, marked by small elongated pale lenticels, coated at first with hoary caducous tomentum, becoming dark brown and rather lustrous or ashy gray, or rarely pale orange color and glabrous or slightly puberulous, or covered with a glaucous bloom in their first winter, growing darker in their second year and much roughened by the large thickened leaf-scars; usually much smaller and at the north rarely more than 40° tall. Winter-buds slightly resinous, broadly ovoid, acute, with bright red-brown scales, about ¼′ long and about one half the size of the flower-buds. Bark on young trunks divided by shallow fissures into broad flat ridges separating on the surface into thick plate-like scales, becoming on old trunks ¾′—1′ thick, light brown tinged with red, and broken into long narrow plates attached only at the middle and sometimes persistent for many years. Wood dull brown, with thin lighter brown sapwood of 12—15 layers of annual growth; now often manufactured into lumber in the valley of the Mississippi River and in the Gulf states, and as black poplar used in the interior finish of buildings.
Distribution. Southington, Connecticut, and Northport, Long Island, southward near the coast to southern Georgia, and the valley of the lower Apalachicola River, Florida, through the Gulf states to western Louisiana, and through Arkansas to southeastern Missouri, western Kentucky and Tennessee, southern Illinois and Indiana, and in central and northern Ohio (Williams, Ottawa and Lake Counties); in the north Atlantic states in low wet swamps, rare and local; more common south and west on the borders of river swamps; very abundant and of its largest size in the valley of the lower Ohio and in southeastern Missouri, eastern Arkansas, and western Mississippi.
4. [Populus tacamahacca] Mill. Balsam. Tacamahac.
Populus balsamifera Du Roi, not L.
