SALICACEE. SILVA OF NORTH AMERICA. 151 
POPULUS. 
FLOWERS diccious, solitary on the stipitate variously divided scales of pendulous 
aments ; perianth 0; disk cup-shaped, often oblique; stamens 4 to 60; ovary 1-celled ; 
ovules numerous, ascending. Fruit a 2 to 4-valved capsule. Leaves alternate, usually 
ovate or ovate-lanceolate, penniveined, stipulate, deciduous. 
Populus, Linnzus, Gen. 307 (1737). — Adanson, Fam. Pl. Tremula, Dumortier, Hall Bijdr. Nat. Wet. 146 (1826). — 
ii. 376.— A. L. de Jussieu, Gen. 409.— Endlicher, Gen. Rafinesque, Alsograph. Am. 42. 
290. — Meisner, Gen. 348. — Bentham & Hooker, Gen. iii. Octima, Rafinesque, Alsograph. Am. 42 (1838). 
412. — Baillon, Hist. Pl. ix.252.— Pax, Engler & Prantl Aigiros, Rafinesque, Alsograph. Am. 42 (1838). 
Pflanzenfam. iii. pt. i. 35. Monilistus, Rafinesque, Alsograph. Am. 42 (1838). 
Leuce, Opiz, Seznam, 59 (1852). 
Large fast-growing trees, with watery juice, furrowed bark, soft straight-grained pale or rarely 
hard dark-colored wood, stout terete or angled branches much roughened after their first year by the 
enlarged and thickened leaf-scars, and thick tough and flexible frequently stoloniferous roots. Buds 
terminal and axillary, resinous, covered by several membranaceous scales, those of the first pair small and 
opposite, the others imbricated, increasing in size from below upward, accrescent, and marking the base 
of the branch with persistent ring-like scars.’ Leaves involute in the bud, alternate, usually ovate or 
ovate-lanceolate, entire, dentate with usually glandular teeth, the glands frequently nectariferous at the 
base of the leaf, or lobed, penniveined, often three-nerved from the base, turning yellow and deciduous 
in the autumn, long-petioled, the petioles sometimes laterally compressed, those of the lower leaves fur- 
nished at the apex on the upper side with two nectariferous glands,” leaving when they fall oblong often 
obcordate elliptical arcuate or shield-shaped leaf-scars displaying the ends of three nearly equidistant 
fibro-vascular bundles. Stipules caducous, leaving in falling persistent scars; those of the first leaves 
oblong, concave, rounded at the apex, thick and firm, as large as the bud-scales, smaller higher on the 
branch, and on the last leaves linear-lanceolate, brown and scarious. Flowers dicecious,’ appearing in 
early spring before the unfolding of the leaves in sessile or pedunculate elongated pendulous aments 
from separate scaly buds formed during the previous season in the axils of leaves of the year, the pistil- 
late becoming elongated and rarely erect at maturity. Scales of the ament one-flowered, obovate, gradu- 
ally narrowed into slender stipes, dilated and lobed, palmatifid or fimbriate at the apex, membranaceous, 
glabrous or villous, usually caducous. Disk of the flower broadly cup-shaped, often oblique, entire, 
dentate or irregularly lobed, fleshy or membranaceous, glabrous or rarely villous, stipitate, generally per- 
sistent under the fruit. Stamens from four to twelve or from twelve to sixty or more, inserted on the 
disk ; filaments free, short, light yellow, glabrous; anthers ovate or oblong, attached on the back near 
the base, purple or red, introrse, two-celled, the cells parallel, opening longitudinally. Ovary sessile in 
the bottom of the disk, oblong-conical, subglobose or ovate-oblong, cylindrical or slightly lobed, glabrous 
or rarely villous, with two or three or rarely four parietal placentas ; style short; stigmas as many as 
the placentas, divided into filiform lobes, or broad, dilated, two-parted or variously lobed; ovules numer- 
ous on each placenta, inserted below their middle, ascending, anatropous, short-stalked ; the micropyle 
inferior. Capsule ripening before the full development of the leaves, greenish or reddish brown, 
1 Henry, Nov. Act. Acad. Ces. Leop. xxii. 327, t. 31. oceasionally occur in the United States. (See Davenport, Bot. Ga- 
2 Trelease, Bot. Gazette, vi. 284. zette, iii. 51. Meehan, Proc. Phil. Acad. 1893, 289. — J. G. Jack, 
8 Individual trees, bearing staminate and pistillate aments and Garden and Forest, vii. 163.) 
also aments with staminate and pistillate flowers mixed together, 
