SALICACE, 
SILVA OF NORTH AMERICA. 163 
POPULUS HETEROPHYLLA. 
Swamp Cottonwood. Black Cottonwood. 
Leaves broadly ovate, acute, short-pointed or rounded at the apex, crenately 
serrate ; petioles terete. 
Populus heterophylla, Linnzus, Spec. 1034 (1753). — 
Muenchhausen, Hausv. v. 232. — Marshall, <Arbust. 
Am. 107.— Moench, Biume Weiss. 81.— Wangenheim, 
Nordam. Holz. 85.— Walter, Fl. Car. 248. — Casti- 
glioni, Viag. negli Stati Uniti, ii. 334. — Willdenow, Berl. 
Baumz. 233; Spec. iv. pt. ii. 806; Enum. 1017. — 
Nouveau Duhamel, ii. 181, t. 51. — Borkhausen, Handb. 
Forstbot. i. 547. — Michaux, Fl. Bor-Am. ii. 244. — 
ii. 326; Mém. Soc. Sci. Hainaut, sér. 3, iii. 232, t. 16 
(Monogr. Pop.). —K. Koch, Dendr. ii. pt. i. 488. — 
Watson, Am. Jour. Sci. ser. 3, xv. 185.— Lauche, 
Deutsche Dendr. ed. 2, 316. — Sargent, Forest Trees N. 
Am. 10th Census U. 8. ix. 172.— Britton, Bull. Torrey 
Bot. Club, xiv. 114.— Watson & Coulter, Gray’s Man. 
ed. 6, 487. — Dippel, Handb. Laubholzk. ii. 193, £. 92. — 
Koehne, Deutsche Dendr. 80. 
Desfontaines, Hist. Arb. ii. 466.— Du Mont de Courset, Populus balsamifera, Miller, Dict. ed. 8, No. 5 (not Lin- 
Bot. Cult. ed. 2, vi. 401. — Pursh, Fl. Am. Sept. ii. nus) (1768). 
619. — Nuttall, Gen. ii. 239. — Hayne, Dendr. Fl. 203.— Populus cordifolia, Burgsdorf, Anleit. Anpfl. pt. ii. 177 
Elliott, Sk. ii. 712.—Sprengel, Syst. ii. 244.— Spach, (1787). 
Ann. Sci. Nat. sér. 2, xv. 30 (Revisio Populorum); Hist. Populus argentea, Michaux f. Hist. Arb. Am. iii. 290, t. 
Vég. x. 386. — Torrey, Fl. N. Y. ii. 215. — Seringe, FV. 9 (1813). 
des Jard. ii. 61. — Darlington, Fl. Cestr. ed. 3, 281.— Populus heterophylla, B argentea, Wesmael, De Can- 
Chapman, FZ. 431.— Curtis, Rep. Geolog. Surv. N. Car. dolle Prodr. xvi. pt. ii. 326 (1868) ; Mém. Soc. Sci. Hai- 
1860, iii. 73. — Wesmael, De Candolle Prodr. xvi. pt. naut, sér. 3, iii. 233 (Monogr. Pop.). 
A tree, eighty or ninety feet in height, with a tall trunk from two to three feet in diameter, and 
short rather slender branches which form a comparatively narrow round-topped head ; or usually much 
smaller, especially in the Atlantic states, and at the north rarely more than forty feet tall. The bark 
of the trunk is from three quarters of an inch to an inch in thickness and light brown tinged with red ; 
on old trunks it is broken into long narrow plates attached only at the middle and sometimes persistent 
for several years, and on young trunks it is divided by narrow shallow fissures into broad flat ridges 
separated on the surface into thick plate-like scales. The branchlets are stout and marked with small 
elongated pale lenticels, and contain a thick orange-colored pith ; when they first appear they are coated 
with hoary caducous tomentum, and during their first year are dark red-brown and rather lustrous, or 
ashy gray, or rarely pale orange-color, and glabrous or slightly puberulous or covered with a glaucous 
bloom, and in their second year grow darker and become much roughened by the large thickened leaf- 
scars. The buds are slightly resinous, broadly ovate, acute, and covered with bright red-brown scales 
more or less coated toward the base with pale pubescence ; the leaf-buds are nearly a quarter of an inch 
long and about half the size of the flower-buds. The leaves are broadly ovate, three-nerved, gradually 
narrowed and acute, short-pointed, or rounded at the apex, slightly cordate or truncate or rounded at 
the broad base, which is usually furnished with a narrow deep sinus, and finely or coarsely crenate with 
small incurved glandular teeth; when they unfold they are covered with thick hoary tomentum which 
soon disappears from the upper surface, and at maturity are thin and firm in texture, dark deep green 
above, pale and glabrous below, with the exception of the stout yellow midribs and forked veins which 
are sometimes tomentose, especially on vigorous shoots, rather conspicuously reticulate-venulose, from 
four to seven inches in length and from three to six inches in breadth ; they are borne on slender terete 
tomentose or nearly glabrous petioles from two and a half to three and a half inches long, and in the 
autumn turn dull yellow or brown before falling. The stipules are linear-lanceolate, brown and scarious, 
