Poplars 301 
much, stands smoke and abuse, and is unclean only when the catkins 
fall. It becomes rather a massive object, with open, broad crown, 
when the young, more conical period with slender branch habit is passed. 
The other northeastern native, with a different lance-shaped, tri- 
angular form, and a different tone of foliage (yellowish beneath) — 
P. balsamifera Linn. (265), including its variety candicans, Balsam 
Poplar or Balm of Gilead, so called from the fragrant large brown sticky 
buds, is of more symmetrical, slender, and tapering form; it is adapted 
to planting on roadsides, near houses, and near water, but is somewhat 
more liable to sucker than the former. 
Of exotics that have been much planted — 
P. dilatata Ait. (266), Lombardy Poplar, of Europe, is used mainly 
for its pryamidal, aspiring form, where sentinels are needed as at the 
entrance of paiks, to mark the position of houses, or to make some 
point conspicuous; or in the background to create the impression of 
distance. Its late leaf period and golden-yellow autumn tints are also 
pleasing. Unfortunately it suckers readily. 
P. alba Linn. (267), Siver-leaf Poplar or Abele, also of Europe, 
furnishes a unique material for color effect, with a striking, peculiarly- 
shaped, three- to five-lobed leaf, dark glossy above and silver-white 
downy beneath, the effect being heightened by the greenish-white bark 
of branches and trunk. It, however, suckers worse than any of the 
poplars and hence has fallen into discredit; but is nevertheless useful 
to make conspicuous a high point, or to set off a group of dark firs, etc. 
Two small trees have value in special situations — 
P. tremuloides Michx. (268) and grandideniata Michx. (269), the 
native Common, and the Large-toothed Aspen, which, if grown on good 
soil, make handsome round-headed trees with pleasing foliage; the 
latter especially gives an elegant and airy appearance with its silky 
young foliage, later assuming a glossy, dark green color and somewhat 
leathery texture. It is of roundish shape, with yellowish-green stem and 
branches. It is also less liable to suckering than is the Common Aspen. 
Several Siberian species have been introduced, mainly for their 
special hardiness. Of these there may be mentioned one also for its 
ornamental value, namely: 
P. laurifolia Ledcb. (270), which is the basis for the forms known 
under the names Certinensis (270a), Bereolensis (270b), and Petrovskt 
(270c), differing more or less in the shape of the foliage. The growth 
of these is more sturdy than that of our natives ones, compact and yet 
