SALICACEZ. 
164 SILVA OF NORTH AMERICA. 
glabrous, from one half of an inch to an inch in length, and caducous. The flower aments appear 
from March at the south to the beginning of May at the north; the staminate are broad, densely 
flowered, about an inch long and erect when the flowers first open, but gradually become pendulous by 
the elongation of the thick peduncle, and when fully grown are from two to two and a half inches in 
length, with stout brittle puberulous stems; their scales are narrowly oblong-obovate, brown, scarious 
and glabrous below, divided above into numerous elongated filiform light red-brown lobes, and fugacious 
as the ament lengthens. The stamens vary from twelve to twenty in number, with slender filaments 
about as long as the large dark red anthers, and are inserted on an oblique slightly concave disk with 
a spreading border. The pistillate aments are slender, pendulous, few-flowered, and from one to two 
inches long, with thin glabrous stems; their scales, which are concave and infold the flowers, are linear- 
obovate, brown and scarious, laterally lobed, fimbriate above the middle, and caducous. The ovary is 
ovoid, terete or obtusely three-angled, with slightly concave sides, crowned by a short stout or elongated 
style, deciduous from the fruit, and two or three much thickened and dilated two or three-lobed stigmas, 
surrounded at the base by the thin and scarious deciduous disk which is irregularly divided into 
numerous triangular or linear acute teeth, and raised on an elongated slender stem. In maturing the 
fruiting aments become erect and from four to six inches long and the pedicels half an inch im length; 
the capsules ripen in May, when the leaves are about a third grown, and are ovate, acute, dark red- 
brown, rather thick-walled, two or three-valved, and about half an inch long. The seed is obovate, 
minute, dark red-brown, and surrounded by a thick mass of rather short lustrous silvery white hairs 
which are often more or less tinged with orange-color toward the base. 
Populus heterophylla is distributed from North Guilford, Connecticut, and Northport, Long 
Island, southward near the coast to southern Georgia, through the Gulf States* to western Louisiana, 
and through Arkansas’ to southeastern Missouri,*> western Kentucky and Tennessee, and southern 
Illinois and Indiana.* In the north Atlantic states, where it is rare and local, the Black Cottonwood 
grows in low wet swamps ; in the south Atlantic and Gulf regions it is more common, and grows on the 
borders of river-swamps which are often inundated; and in the valley of the lower Ohio River, in 
southeastern Missouri, eastern Arkansas, and western Mississippi, it is very abundant, growing to its 
largest size on the borders of swamps with the Texas Oak, the Swamp White Oak, the Red Maple, the 
Sweet Gum, and the Sour Gum. 
The wood of Populus heterophylla is light, soft, and close-grained ; it contains numerous very 
obscure medullary rays and small scattered open ducts, and is dull brown, with thin lighter brown 
sapwood composed of twelve or fifteen layers of annual growth. The specific gravity of the absolutely 
dry wood is 0.4089, a cubic foot weighing 25.48 pounds. It is now often manufactured into lumber 
in the valley of the Mississippi River and in the Gulf states, and under the name of black poplar is 
used in the interior finish of buildings. 
Populus heterophylla was first described in the Natural History of Carolina,’ published in 1731 
by Mark Catesby, who discovered it in the coast region of South Carolina. According to Aiton,® it 
was cultivated in England by Dr. John Fothergill’ as early as 1765, and it is now occasionally found 
in gardens in the United States and Europe. 
1 I have no evidence that Populus heterophylla grows in Florida, 
but as it is abundant in the alluvial swamps of the Mobile River 
and on the lower Tombigbee and Alabama Rivers in Alabama, it 
probably ranges eastward at least as far as the valley of the Ap- 
palachicola. 
* Harvey, Am. Jour. Forestry, i. 456. 
8 Bush, Rep. State Board Hort. Missouri, 1895, 359. 
* Ridgway, Proc. U.S. Nat. Mus. v. 86; Bot. Gazette, viii. 
350. 
5 Populus nigra folio maximo gemmis Balsamum odoratissimum 
JSundentibus, i. 34, t. 34.— Charlevoix, Histoire de la Nouvelle 
France, ed. 12™, iv. 336, f. 48. —Romans, Nat. Hist. Florida, 26. 
Populus magna foliis amplis, aliis cordiformibus, alits subrotundis, 
Junoribus tomentosis, Clayton, Fl. Virgin. 194. 
Populus foliis cordatis crenatis, Linneus, Hort. Cliff. 460.— 
Royen, Fl. Leyd. Prodr. 82. 
Populus alba majoribus foliis subcordatis, Romans, Nat. Hist. 
Florida, 26. 
§ Hort. Kew. iii. 407. — Loudon, Arb. Brit. iii. 1672, f. 1534. 
7 See vi. 16. 
