Six kinds of Poplar are commonly grown in this
country, of which three are regarded as indigenous
species. These are the Aspen, the Grey Poplar
and the Black Poplar. Then, of common introduced
species, we have the White Poplar, the Lombardy
Poplar and the hybrid Black Italian Poplar.
The Poplars share their love of the Willows for
moist places. Their growth is rapid, and their
timber, consequently, is of little value, though
its softness and lightness render it suitable
for many uses, such as box-making and flooring.
An additional point in favour of White Poplar
for the latter purpose is its unreadiness to burn.
The Poplars and the Willows agree broadly in the
construction of their flowers in catkins, but
whereas the Poplars have broad leaves and drooping
catkins, the Willows, with few exceptions, have
long, slender leaves and erect catkins. The sexes
are not only in distinct flowers, but on separate
trees, and the males appear to be far more numerous
than the females. In the popular sense there are
no flowers, for there are neither sepals nor petals,
each set of sexual organs being protected merely
by a scale. The catkins usually appear before
the leaves. As there is nothing to attract insects
to the work, the Poplars have to rely upon the
wind for conveying the pollen to the female trees.
The White Poplar, or Abele (Populus alba), is
not so tall a tree as the Grey Poplar, generally
not exceeding fifty feet in this country. Covered
with smooth grey bark, its branches spread horizontally,
and its lobed, maple-like leaves are hung on long,
slender foot-stalks, which are flattened at the
sides, so that when moved by the wind they flutter
laterally. The leaves vary in shape. Those on
long vigorous shoots and suckers are large, triangular
in shape and deeply lobed. They are slightly hairy
on the upper surface and covered with a dense
snow-white felt on the under side. The leaf buds
and young twigs are similarly covered. The leaves
on the short shoots are oval, less deeply lobed
and often not so densely hairy on the under surface.
The catkins, which appear in March and April,
are cylindrical; those of the male trees are rarely,
if ever, seen in Britain. The female catkins are
about an inch long, the two yellow stigmas are
slender, with slit tips, and the ovaries develop
into slender egg-shaped capsules, each with its
In July when the seed capsules open, the surrounding
vegetation and ground are thickly strewn with
the long, white cotton filaments attached to the
The wood of this tree is softer and spongier than
that of other Poplars. This species is said not
to produce flowers in Scotland.
The Grey Poplar (Populus canescens), which is
thought to be indigenous only in central and southern
England, attains to eighty or ninety feet, with
a girth of ten to twenty-four feet. Its life extends
to about a century, but its wood is considered
best between fifty and sixty years of age.
The leaves on the short shoots are shaped like
those of the White Poplar, but their undersides
are either coated with grey down or are quite
smooth; those of the long shoots have their margins
cut into angles and teeth. The female flowers
mostly have four wedge-shaped purple stigmas,
which are cleft into four at their extremities.
The Aspen (Populus tremula) does not attain either
to so large a size or so moderate an age as the
Grey Poplar. Its height, when full-grown, is from
forty to eighty feet, and after fifty or sixty
years its heart-wood begins to decay, and its
destruction is then hastened by the attacks of
such internal-feeding insects as the caterpillars
of the Goat-moth and the Wood Leopard-moth.
The leaves on the branches are broadly egg-shaped,
the waved margin cut into teeth with turned-in
points. In one form (var. villosa) the leaves
are covered beneath with silky or cottony hairs;
in the other form (var. glabra) they are almost
smooth. The leaves on the suckers are heart-shaped,
with glandular teeth. The leaf-stalks are longer
than those of its congeners, so that they are
constantly on the flutter.
The catkins which are two or three inches long
are similar to those of the White and Grey Poplars,
but the scales have jagged edges.
It is indigenous in all the British Islands as
far north as Orkney, but, though commonly found
in copses on a moist, light soil, is more frequent
as a planted tree in gardens and pleasure grounds.
It is a characteristic tree of the plains throughout
the Continent, but ascends to 1,600 feet in Yorkshire,
and in the Bavarian Alps is found as high as 4,400
feet. It is not deep-rooted, and the root-branches
run almost horizontal. Where accessible to cattle
and deer, the foliage of the suckers is eagerly
browsed by them.
The Black Poplar (Populus nigra) appears to be
so called, not by reason of any blackness of leaf
or bark, but because of the absence of any white
or grey down on the underside of its leaves. Its
bark is grey, and readily distinguished by the
great swellings and nodosities that mar the symmetry
of its trunk.
It is a tree of erect growth, fifty or sixty feet
in height, with horizontal branches, and leaves
that vary in shape from triangular to almost circular,
and in width from an inch to four inches. They
have rounded teeth on the margins, and in their
young state the underside is silky.
The flowers in the catkins are not densely packed.
Those of the male are two or three inches in length,
and dark red in colour; their abundance before
the tree has put out its leaves makes the male
tree a conspicuous object. The female catkins
are shorter and do not droop. When the roundish
capsules burst in May or June to distribute their
seeds, the white cotton with which the latter
are invested gives prominence to the female tree.
The wood is chiefly used by the wood-turner; in
Holland, where it is extensively cultivated, it
provides the material for sabots.
The Black Poplar is indigenous in the eastern
counties and in Wales. Some botanists regard the
Lombardy Poplar as a variety of the Black Poplar,
as apart from the very different habit of the
tree – not by itself sufficient grounds
for separation – there is little else to
The Lombardy Poplar (Populus italica) was for
many years a tree of mysterious origin. It appeared
in Italy about the middle of the eighteenth century,
and was called Lombardy Poplar in consequence
of its introduction thence by Lord Rochford in
1758. The original was a male tree, and as practically
all of the vast number of Lombardy Poplars now
existing have descended from cuttings or suckers
of that tree, they are also males. The general
supposition is that the original tree arose as
a sport from the Black Poplar. A few females are
known to exist, and these are probably the offspring
of a later crossing.
Its glossy leaves are shaped like those of the
Black Poplar, but its branches, instead of spreading,
all grow straight upwards, so that the spire-shape
of the tree is produced – a shape only found
otherwise among coniferous trees, particularly
in the Cypress, the Juniper and the Irish Yew.
It is its form, great height (80 to 100 feet),
and rapidity of growth that have led to its wide
use here as an ornamental tree. Its growth is
extremely rapid, especially during its first twenty
years, when it will attain a height of sixty feet
or more, provided it be grown in good, moist (but
not marshy) soil.
Its wood is, of course, of little value, and is
chiefly used for making boxes and packing-cases,
where its lightness, combined with toughness and
cheapness, is an advantage.
The bark is rough and deeply furrowed; the furrows
are spiral. Like the Black Poplar, it has smooth
shoots, and the unopened buds are sticky.
The Black Italian Poplar (Populus serotina) appeared
in the eighteenth century apparently as a result
of the crossing of the Black Poplar with an American
species (P. deltoidea).
The stem is free from the swellings and burrs
of the Black Poplar and the spreading, ascending
branches form a fan-like crown. The leaves are
oval, about three inches broad, toothed and fringed.
It comes into leaf much later than any other Poplar
and is probably the commonest Poplar to be seen
in the British Isles.
The Ontario or Balsam Poplar (Populus candicans)
is of unknown origin. Usually known as the Balsam
Poplar in this country it is frequently found
as a planted tree. It is often confused with the
American Balsam Poplar (P. tacamahaca), which
is rarely seen in cultivation in England. The
Ontario Poplar has broadly ovate leaves which
are dark-green with few hairs on the upper surface
and whitish on the lower surface. It produces
The distinctive character of the tree is the fragrance
of its young foliage, which scents the air on
moist evenings, and makes it a desirable tree
to plant near water.