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1658 ARBORETUM AND FRUTICETUM. PART 11]. 
It comes into leaf, in the climate of London, 
in the last week of April, or in the beginning 
of May; about which time the male catkins 
have chiefly dropped off. The cottony seed 
is ripe about the middle of May, and is so 
abundant, even in young trees, as to cover the 
ground under them like a fall of snow. When 
young, the tree shoots up with a strong erect 
stem, which is much less liable to put out 
timber-like branches than any other poplar 
whatever, except P. fastigiata and P. balsa- 
mifera. The rate of growth, in the climate of 
London, on good soil, is between 30ft. and 
40 ft. in 7 years; and even in Scotland it has 
attained the height of 70 ft.in 16 years. There 
appears to be little doubt of its being a native 
of America; but, as Pursh has only seen it in 
gardens there, and neither Michaux nor his 
father had ever seen it there at all, we think it probably only a cultivated 
variety of P. canadénsis ; which, as we have before observed, comes so near the 
P. nigra of Britain, as to induce us to think that they are not specifically dif- 
ferent. P.monilifera was introduced into England in 1772, from Canada; but, 
as it is figured in Abbott and Smith’s Natural History of Georgia, vol. ii. t.71., 
it appears to be also a native of that country. After its first introduction, it 
does not appear to have been much cultivated for some years, when it was 
brought into notice by Messrs. Archibald Dickson and Co., of Hasendeanburn 
Nursery, under the name of the black Italian poplar. Its history under this name 
is thus given in Pontey’s Profitable Planter : — Messrs. Dickson obtained the 
plant from a gentleman in their neighbourhood, who had received it from his 
son, then residing in North America. Mr. Archibald Dickson then travelled 
for the firm through most of the northern districts of England; and, having 
ahigh opinion of this poplar, of which he had been the first to procure a 
stock of plants, he recommended it every where. The name of the black 
Italian poplar he accounted for to Mr. Pontey, by saying that he had learned 
that this sort of peplar was common in Italy, as well as in America. Mr. 
Pontey adds, in confirmation of Mr. Dickson’s statement: “ As I can now 
recollect his having so recommended the article, and also having bought our 
first stock from him, in or about the year 1787, I have, therefore, good reason 
to suppose his account is in every respect accurate: indeed, it stands strongly 
confirmed by the age of the trees found on the southern verge, and within his 
route, as they are much older than those to the south of it; and, therefore, I 
think Messrs. Dickson entitled to the credit of having first recommended and 
disseminated a tree, the rapid growth of which, in addition to its being highly 
ornamental, will prove of essential benefit to the country.” (Pontey’s Prof. 
Planter, p. 218.) This was written in 1813, when Mr. Pontey published 
the first edition of his book; and the black Italian poplar has, since that 
period, been far more extensively planted in Britain than any other species 
or variety of the genus. Notwithstanding this evidence in favour of its being 
a native of North America, we think (as we believe all the white-barked pop- 
lars, such as P. nigra, P. canadénsis, P. betuleefolia, P. fastigiata, and P. angu- 
lata, to be different forms of one species) that P. monilifera may have been 
originated in Italy or Switzerland, and carried out to North America ; and, if 
so, this will readily account for the English name of black Italian, the 
American name, mentioned by Michaux and Browne, of Swiss poplar, and the 
French name of Peuplier Suisse. We have heard of a plant of P. fastigiata, 
which appears to be throwing out a side branch of P. monilifera; but we are 
not authorised at present to state any particulars respecting it. The female 
catkins of the two kinds appear so much alike, as to leave no doubt in our 
minds of their identity as species. 
