SALICACER. 169 
SILVA OF NORTH AMERICA. 
The wood of Populus balsamifera is light, soft, not strong, and close-grained; it contains 
numerous obscure medullary rays and many minute scattered open ducts, and is light brown, with 
thick nearly white sapwood. The specific gravity of the absolutely dry wood is 0.3635, a cubic foot 
weighing 22.65 pounds. It is made into paper-pulp, and in northern Michigan is manufactured into 
pails, tobacco boxes, and small packing-cases. On the northern shores of the Great Lakes the thick 
bark from the base of old trunks is used as a substitute for cork to float fishermen’s nets. 
In the northeastern United States and in Canada the Balm of Gilead, Populus balsamifera, var. 
candicans,' is frequently cultivated as a shade - tree. 
spreading branches, forming a broader and more open head, in its broader cordate leaves which are 
more coarsely serrate with gland-tipped teeth, more or less pubescent when young and at maturity paler 
on the lower surface, ciliate on the margins with short white hairs, and usually pubescent along the ribs 
and principal veins, and in its pubescent petioles and rather heavier wood. 
It differs from the common form in its more 
The Balsam Poplar, which is the largest of the subarctic trees of America, is the most conspicuous 
feature of vegetation over areas thousands of square miles in extent, and its great size, its stately trunk, 
and the brilliancy of its leaves, displaying in turn, as the wind plays among its branches, their dark 
green upper and their rusty lower surfaces, often make it a splendid object. 
According to Aiton, Populus balsamifera was introduced into English gardens in 1731.? 
1 Populus balsamifera, var. candicans, Gray, Man. ed. 2, 419 
(1856). — Watson, Am. Jour. Sci. sér. 3, xv. 135.— Bull. Torrey 
Bot. Club, vii. 57. — Lauche, Deutsche Dendr. ed. 2, 318. — Sargent, 
Forest Trees N. Am. 10th Census U.S. ix. 173. — Watson & Coulter, 
Gray’s Man. ed. 6, 487. 
Populus candicans, Aiton, Hort. Kev. iii. 406 (1789). — Willde- 
now, Berl. Baumz. 231; Spec. iv. pt. i. 806; Enum. 1017.— 
Borkhausen, Handb. Forstbot. i. 545.— Michaux f. Hist. Arb. 
Am, iii. 308, t. 13, f. 2.— Pursh, Fl. Am. Sept. ii. 618. — Poiret, 
Lam. Dict. Suppl. iv. 378. — Nuttall, Gen. ii. 239. — Hayne, 
Dendr. Fl. 202.— Bigelow, Fl. Boston. ed. 2, 370.— Sprengel, 
Syst. ii. 244. — Hooker, Fl. Bor.-Am. ii. 154.— Fischer, Garten- 
zeit. ix. 403; Bot. Reg. xix. Misc. 22.— Torrey, Fl. N. Y. ii. 
217. — Audubon, Birds, t. 59.— Spach, Ann. Sci. Nat. sér. 2, 
xv. 33 (Revisio Populorum); Hist. Vég. x. 392.— Emerson, Trees 
Mass. 245 ; ed. 2, i. 281. —Seringe, Fl. des Jard. ii. 63. — Gray, 
Man. 431.— Wesmael, Bull. Féd. Soc. Hort. Belg. 1861, 334, f. 
12 (Monogr. Pop.) ; De Candolle Prodr. xvi. pt. ii. 330 ; Mém. 
Soc. Sci. Hainaut, sér. 3, iii. 248, t. 9 (Monogr. Pop.). — Dippel, 
Handb. Laubholzk. ii. 203 (excl. var. a).— Koehne, Deutsche 
Dendr. 83. 
The origin of this noble and beautiful tree is uncertain. It does 
not appear to be indigenous in New England or eastern Canada, 
where the pistillate plant has been used as a shade-tree from very 
early times, as it has been in the middle states and in Europe. It is 
stated by Professor L. H. Bailey (Bot. Gazette, v. 91; Bull. No. 68, 
Cornell University, Hort. Div. 221 [The Cultivated Poplars]) to be 
indigenous in Michigan, where it is said that groves of it existed 
when the country was first settled, and were afterward cut down 
for lumber. I have not seen it except in the neighborhood of 
human habitations or in specimens taken from trees which had 
evidently been cultivated. The width of the leaves, their ciliate 
margins, and pubescence are the only characters for distinguishing 
it from the ordinary forms of Populus balsamifera, and they hardly 
afford sufficient grounds for considering it, as many authors have 
done, specifically distinct, at least until more knowledge with re- 
gard to it as a wild tree is obtained. 
2 Hort. Kew. iii. 446.— Loudon, Arb. Brit. iii. 1637, £. 1535, 
1536, t. 
