CHAP. CIII. SALICA‘CEX. PO’PULUS. 164) 
older branches is grey. In the beginning of April, the 
male catkins, which are generally about 3 in. in length, 
appear; and, about a week afterwards, the female catkins, 
which are shorter, come forth: a week after the expan- 
sion of the flowers of the female catkins, the males drop 
off; and, in five or six weeks afterwards, the seeds wii 
have ripened and dropped also. The seeds are enclosed 
in a hairy or cottony covering ; in consequence of which, 
they are wafted to a great distance by the wind. The 
growth of all the varieties is extremely rapid; so that a 
tree, 10 years planted, in soil moderately good and 
moist, will attain the height of 30 ft., or upwards, with 
a trunk from 6in, to 9in. in diameter; as has been the 
case with several trees in the Horticultural Society’s 
Garden. As a proof of the rapidity of the growth of 
the abele tree, Evelyn mentions one of these trees at 
Syon, “ which, being lopped in February, 1651, did, by %% ' 
the end of October, 1652, produce branches as big as 1508 
a man’s wrist, and 17 ft. in height.” Truncheons of the white poplar, 9 ft. 
long, planted on the banks of a stream, some yards from the current, had, in 
12 years, trunks nearly 10 in. in diameter; and had heads in proportion. ( Bath 
Soc. Papers, 1786, vol. iii. p. 90.) The duration of the tree rarely exceeds 
two centuries ; but, when it is to be cut down for timber, it should be seldom 
allowed to exceed 50 years’ growth, as the heart-wood at that period, on most 
soils, begins to decay. Mitchell says that, on the banks of rivers, the tree is 
at its full value in 40 or 50 years; but that, in dry situations, it will require 
from 50 to 70 years to mature it. (Dendrologia, &c., p. 51.) Inthe Dictionnaire 
des Eaux et Foréts, it is stated, that a tree planted in a field, and surrounded 
by a fence at 25 ft. distance from it on every side, formed by its suckers, in 
20 years, a circular clump of wood 50 ft. in diameter; and, consequently, 
that 30 or 40 trees would cover an acre with a thick wood in the same space 
of time. Hence it follows, that, when the tree is once introduced into woods, 
especially where the soil is loamy and moist, it forms a perpetual succession 
of young trees, however frequently these may,be cut down. When treated 
as coppice-wood, the abele is by no means a durable plant ; the stools decay- 
ing after they have borne three, or at most four, crops of poles. 
Geography. The common grey poplar (P. (a) canéscens) is generally sup- 
posed .to be a native of Britain, as well as of France and Germany; but the 
abele tree (P.alba) is thought by some to have been first brought to England 
from Flanders. This we think highly probable; and it is favourable to our 
opinion that P. alba and its varieties ought to be considered. as cultivated 
forms of P. canéscens, P. alba and P. (a-) canéscens are indigenous to Europe, 
as far north as 56° or 57°; and they are found throughout the south of Eu- 
rope, Caucasus, Persia, and Barbary. They grow in most districts of Britain; 
and a few stunted plants of P. alba are said by M‘Culloch to comprise all the 
trees in the Island of Lewis. Whether these trees in Lewis belong to P. alba, 
or P, (a.) canéscens, may, however, be doubted. Turner, in 1568, says, “ the 
white aspe is plentifull in Germany and Italy;” but that he does not remember 
to have seen it in England. Gerard, who wrote 30 years after Turner, found 
the white poplar at Blackwall, near London ; at Oyenden, in Essex; and a few 
other places. Dr. Walker, writing in 1773, says that it is doubtful whether 
the abele is a native of England ; but that it certainly has the appearance of 
being indigenous in several parts of Scotland. But it must be recollected 
that, in his time, P. alba and P. (a.) canéscens were considered as synonymous. 
He adds, also, that the abele was planted in many places in Scotland about the 
end of the seventeenth century ; and that it had been afterwards neglected and 
despised, in consequence of the great number of suckers that it threw up all round 
it from its creeping roots. Hartlib, in his Compleat Husbandman (published in 
1659), states that, some years before the time of his writing, there were 10,000 
7 
