﻿Trees of New York State 133 



SALICACEAE 



Populus heterophylla L. 



Swamp Cottonwood, Swamp Poplar, Black Cottonwood 



Habit — In New York State a small tree 25-40 feet in height ivith a trunk 

 diameter of 12 inches or less, farther south sometimes 90-100 feet tall. 

 Crown rather narrow, open, round-topped, consisting of a few large limbs 

 which are irregularly arranged. Bole in large trees straight and columnar, 

 bearing a high crown. In small trees it is much shorter and tapering, and 

 continues into the crown. 



Leaves — Alternate, borne on long, hairy, terete petioles, broadly ovate, 

 obtuse or subacute at the apex, roimded to cordate at the base, crenate, 

 4-8 inches long 3-5 inches wide, at first densely hoary-pubescent, at 

 maturity thin but firm in texture, dark green and smooth above, paler 

 and glabrous below. Stipules linear-lanceolate, 14-I inch long, fugacious. 



Flowers — Appearing in April or May before the leaves from separate flower- 

 buds, dioecious, borne in the axils of bro-mi, oblong-obovate scales which 

 are divided above into numerous filiform lobes, the whole forming anients. 

 Staminate aments cylindrical, stout, densely flowered, at first short and 

 erect, finally pendant, 2-2 1^ inches long. Pistillate aments broad, cylin- 

 drical, few flowered, pendant, 1-2 inches long. Stamens 12-20, with 

 short, slender filaments and dark red anthers, inserted on an oblique 

 shallow disk. Pistil solitary, enclosed at the base in the campanulate, 

 lobed, deciduous disk, consisting of an ovoid ovary, a short style and 2-3 

 spreading, lobed stigmas. 



Fruit — An ovoid-oblong smooth, thick- walled, long-pedicellate, reddish brown 

 capsule, about V^ of an inch long. The capsules are borne loosely in 

 naked, erect or ascending aments 4-6 inches long and open in May when 

 the leaves are about half gro-mi by 2-3 sutures to set free the mdnute, 

 dark brown, white-comose seeds. 



Winter characters — Twigs stout, lenticellate, at first velvety, soon becoming 

 lustrous or dull grayish or reddish brown, with conspicuous orange- 

 colored pith. Flower- and leaf-buds distinct. Leaf-buds ovate, acute, 

 puberulous, reddish brown, covered by 4-7 scales, about V4, of an inch long. 

 Flower-buds similar, broadly ovate, more strongly divergent, about ^/^ of 

 an inch long. Mature bark light reddish brown and thick, with narrow, 

 shallow fissures and long, narrow, flat ridges. 



Habitat — A moisture-loving tree occurring intermixed with other species in 

 low, swampy situation, often where the soil is inundated for long periods 

 each year. 



Range — Connecticut south in the coastal swamps to Georgia, through the Gulf 

 States to western Louisiana, thence north in the Mississippi basin to Ken- 

 tucky and Missouri. Zone A. 



Uses — Of little economic significance. Wood light, soft, weak, close-grained, 

 pale brown with thin, brownish white sapwood. Occasionally sawed into 

 lumber in the lower Mississippi basin. 



