SALICACE. 
152 SILVA OF NORTH AMERICA. 
glabrous or villous, oblong-conical, subglobose, or ovate-oblong, one-celled, separating at maturity into 
from two to four thin or thick recurved valves placentiferous below the middle. Seed exalbuminous, 
minute, broadly obovate, or ovate, rounded or acute at the apex, surrounded by a tuft of long soft white 
hairs attached to the short funiculus and deciduous with it; testa light chestnut-brown. Embryo 
straight, filling the cavity of the seed ; cotyledons elliptical, much longer than the short radicle turned 
toward the minute hilum.’ 
Populus inhabits boreal and temperate regions in the northern hemisphere, often in the extreme 
north covering great areas with nearly pure forests, and ranging southward in the New World to 
northern Mexico, and Lower California, where one endemic species occurs,’ and in the Old World 
to northern Africa and the southern slopes of the Himalayas, upon which Populus ciliata* and 
Populus microcarpa‘ are found. Of the eighteen or nineteen species® which have been distinguished, 
nine inhabit British America and the United States, where Poplars are distributed from within the 
Arctic Circle to Mexico, and from the shores of the Atlantic Ocean to those of the Pacific, lining the 
banks of streams in the northern and central regions of the continent, and growing on high mountain 
slopes. In the eastern hemisphere Poplars extend north of the Arctic Circle and abound im northern 
and central Europe, and in northern and central Asia, where they are often the most conspicuous 
feature of vegetation.® 
1 The species of Populus may be grouped in the following sec- 
tions proposed by Sereno Watson (Am. Jour. Sci. ser. 3, xv. 135) :— 
1. Stigmas two, two or three-lobed, with narrow or filiform lobes. 
Capsule oblong-conical, thin-walled, two-valved. Leaves ovate ; 
petioles laterally compressed. Buds slightly resinous, glabrous or 
pubescent. (Sections Leuce [Duby, De Candolle Syn. Pl. Fl. Gall. 
ed. 2, i. 427 (1828)] and Leucoides [Spach, Ann. Sci. Nat. sér. 2, 
xv. 30 (1841) (Revisto Populorum)].) 
2. Stigmas from two to four, dilated, two-lobed, their lobes 
variously divided. Capsule subglobose to ovate-oblong, usually 
thick-walled, two to four-valved. Leaves ovate, cordate, lanceolate 
or deltoid ; petioles terete or laterally compressed. Buds very 
resinous. (Sections Aigeiros [ Duby, J. c. (1828) ] and Tacamahaca 
[Spach, 2. c. 32 (1841)].) 
2 Populus Monticola, Brandegee, Zoé, i. 274 (1890). — Sargent, 
Garden and Forest, iv. 330, £. 56. 
Populus Monticola, which is the American representative of the 
Old World Populus alba, and a tree often nearly a hundred feet in 
height, with a tall thick trunk, young branches and buds coated 
with hoary tomentum, and broadly ovate leaves covered with silky 
white hairs, inhabits cafions of the high mountains in the interior 
of southern Lower California, following them down toward the 
warm lowlands, where it grows to its largest size, and where it 
was discovered in January, 1890, by Mr. T. S. Brandegee, who 
found it flowering in February and losing its leaves in the early 
autumn months when other plants associated with it, stimulated by 
the late summer rains of the region, were just entering the period 
of active vegetation. 
Unlike that of other Poplars, the wood of this noble tree is 
light red, hard and heavy, with a handsome satiny surface capable 
of receiving a high polish. (See Garden and Forest, vi. 190.) 
3 Royle, Jil. ii. 346, t. 84, f. 1 (1839). — Wesmael, De Candolle 
Prodr. xvi. pt. ii. 329; Mém. Soc. Sci. Hainaut, sér. 3, iii. 243, t. 5 
(Monogr. Pop.). — Hooker f. Fl. Brit. Ind. v. 638. 
This is a large tree common in the mixed forests of the tem- 
perate Himalayas from Cashmere to Bhutan. Water-troughs and 
other articles of domestic use are made from the wood, and the 
leaves are used as fodder for goats (Brandis, Forest Fl. Brit. Ind. 
476. — Gamble, Man. Indian Timbers, 379). 
4 Hooker f. /. c. 639 (1890). 
5 In addition to the species of Poplars of which several are still 
very imperfectly known, a number of plants believed to be hybrids 
have appeared at different times either naturally or as the result 
of artificial fecundation, and the ease with which the trees of this 
genus appear to intercross adds to the difficulty of understanding 
many of the Old World forms, which seem to be hopelessly confused. 
In The Gardener’s Chronicle (n. ser. xviii. 108) five hybrid Poplars 
from the Forest School at Petrovskoi-Rasoumovskoi, near Mos- 
cow, are described ; and hybrid Poplars are also described by Karl 
Koch ( Wochenschr. Gartn. und Pflanzenk. viii. 225), Dippel (Handb. 
Laubholzk. ii. 204, 208), and Koehne (Deutsche Dendr. 78, 84, 85). 
6 The two common Poplars of northeastern Asia have often been 
considered varieties of the North American Populus balsamifera ; 
but Maximowiez, who had unrivaled opportunities for studying 
these trees in their native forests, considered them distinct from 
the New World species, owing to the form of their leaves and their 
sessile or subsessile capsules, and his views are probably correct, 
although, as he suggested, trees of this group in cultivation may 
have been so changed by the intercrossing of the American and 
Asiatic species that it is not always possible to distinguish the cul- 
tivated plants specifically (Bull. Soc. Nat. Mosc. liv. pt. i. 51). 
The most widely distributed of these trees is, — 
Populus suaveolens, Fischer, Gartenzeit. ix. 404 (1841). — Lede- 
bour, Fl. Ross. iii. 629. — Turczaninow, Fl. Baicalensi-Dahurica, ii. 
125. — Maximowicz, Mém. Sav. Etr. Acad. Sci. St. Pétersbourg, ix. 
245 (Prim. Fl. Amur.). — Regel, Mém. Acad. Sci. St. Pétersbourg, 
sér. 7, iv. 132 (Tent. Fl. Ussur.) ; Bull. Soc. Nat. Mosc. xxii. pt. 
i. 398. —Fr. Schmidt, Mém. Acad. Sci. St. Pétersbourg, sér. 7, xii. 
174 (Fl. Sachalinensis). — Koehne, Deutsche Dendr. 84. 
Populus balsamifera, Pallas, Fl. Ross. i. 67, t. 41 (not Linneus) 
(1784). — Hooker & Arnott, Bot. Voy. Beechey, 117. — Trautvet- 
ter, Act. Hort. Petrop. ix. 189 (Incremente Fl. Ross.) (in part). — 
Brandis, J. c. — Hooker f. 1. c. 638. 
Populus balsamifera suaveolens, Loudon, Arb. Brit. iii. 1674 
(1838). — Wesmael, De Candolle Prodr. 1. c. 330 (excl. hab. 
America) ; Mém. Soc. Sci. Hainaut, l. c. 246, t. 6. — Dippel, l. c. 
206 (in part). 
Populus pseudobalsamifera, Fischer, 1. c. 403 (1841). 
