LXVIII. SALICA‘CEH: PO/PULUS. 821 
bracteas of the fertile flowers are, also, more deeply and regularly cut. The 
branches are more upright and compact. The leaves are rounder, more 
conspicuously 3-ribbed, and less deeply or acutely lobed ; not folded in the 
bud, and without gum. They are downy beneath ; but the down is chiefly 
greyish, and not so white or cottony as in P. Alba: in some instances the 
leaves are glabrous. (Smith.) A tree closely resembling the preceding 
species, and found in similar situations. 
The wood of the white poplar weighs, when green, 581b. 30z. per cubic 
foot ; and in a dried state, 38 lb. 70z.: it shrinks and cracks considerably in 
drying, losing one quarter of its bulk. The wood of P. (a.) canéscens is said 
to be much harder and more durable'than that of P. alba; in the same manner 
as the wood of the Tilia europz’a parvifolia is finer-grained and harder than 
that of 7. e. grandifolia. The wood of both kinds is the whitest of the genus ; 
and it is used, in France and Germany, for a variety of minor purposes, par- 
ticularly when lightness, either of weight or colour, is thought desirable; or 
where an artificial colour is to be given by staining. It is excellent for form- 
ing packing-cases, because nails may be driven into it without its splitting. It 
is used by the turner and the cabinet-maker, and a great many toys and small 
articles are made of it. The boards and rollers around which pieces of silk 
are wrapped in merchants’ warehouses and in shops are made of this wood, 
which is peculiarly suitable for this purpose, from its lightness, which prevents 
it much increasing the expense of carriage. The principal use of the wood of 
the white poplar in Britain is for flooring-boards ; but for this purpose it 
requires to be seasoned for two or three years before using. For the abele to 
attain a large size, the soil in which it is planted should 
be loamy, and near water ; though on a dry soil, where 
the tree will grow slower, the timber will be finer-grained, 
and more durable. In British nurseries, it is commonly 
propagated by layers; which, as they seldom ripen the 
points of their shoots, or produce abundance of fibrous 
roots the first season, ought to be transplanted into 
nursery lines for at least one year before removal to 
their final situation. The tree is admirably adapted for 
thickening or filling up blanks in woods and plantations ; 
and, for this purpose, truncheons may be planted 3 in. 
or 4in. in diameter, and 10 ft. or 12 ft. high. Owing to 
the softness of the wood, and its liability to shrink and 
crack, it is dangerous to cut off very large branches; 
and, even when branches of moderate size are cut off, 
the wound ought always to be covered over with graft- 
ing clay, or some description of plaster, to exclude Y 
the air. The tree is considered, both by French and ys. p. (a.) canéscens. 
English authors, as bearing lopping worse than any 
other species of the genus; and, when transplanted, the head should never 
be cut off, and not even cut in, unless in cases where the tree is to be planted 
in a hot and dry soil. 
¥ 3. P.rre’muLa L. The trembling-leaved Poplar, or Aspen. 
if ‘on. Lin. Sp. Pl., 1464.; Eng. Fl., 4. p- 244.3 Hook. Fl. Scot., 289. . 
eae Pilibyca Hail Sym. 456. Sp gbrida Dod. Pemipt. 836.3 P. nigra Trag. Hist. 1033. 
fig.; P. péndula Du Roi; Aspe; le Tremble, Fr.; la Tremola, Alberalla, Alberetto, Ital. ; 
iB. 
itter-. 1, Espe, Ger. 7 
ne eaiee rhe E nglish name of Aspen or Aspe is evidently derived from the German, espe. 
The Sexes. Both sexes are described in the English Flora. : . : Fe 
Engravings. Eng. Bot., t. 1909.; Hayne Abbild., t. 203. ; the plate in Arb. Brit., Ist edit., vol. vii. ; 
and our fig. 1494. 
Spec. Char., §c. Young branchlets hairy. Leaves having compressed foot- 
stalks, ‘and disks that are roundish-ovate, or nearly orbicular ; toothed in a 
repand manner, ‘downy when young, afterwards glabrous on both surfaces. 
Stigmas 4, erect, eared at the base. (Smith.) Alarge tree, but seldom seen 
so high as P. Alba, Europe; inrather moist woods. Height 50 ft. to 70 ft. 
. 36 3 
