noticed by any writer on forestry. Other poplars of all sorts, including
the black poplar whereof this is only a variety, mingle branches freely
with their neighbours; but the Lombardy poplar is a regular
_Sainte-Nitouche_, and will not suffer contact with any other tree, even
one of its own race. A curious example of this may be seen in London.
When the Buckingham Palace Hotel was built, somewhere about 1860, Queen
Victoria desired that a screen of trees should be planted within the
Palace enclosure to shut the hotel out of view. The Office of Works
chose the Lombardy poplar, calculating that it would form a lofty, thick
hedge. Not a bit of it! The trees died rather than touch each other;
they have been replaced times without number; but the Office of Works
has never discerned the secret of their temperament, and continue their
task of Sisyphus year after year, filling the gaps caused by death with
trees of the same kind. Had a row of true planes been set there at
first, the privacy of the Palace would have been secured long before
this.
Despite this constant characteristic of the Lombardy poplar, which
anybody may verify for himself by examining the fine groups of them near
Maidenhead and Windsor, Selby committed himself to the extraordinary
statement that this tree, "planted so as to form a hedge, and being cut
even at a certain height and regularly trimmed, becomes a thick and
verdant hedge."[11]
The asp (_Populus tremula_) is now generally spoken of by the adjectival
form "aspen." Its ceaseless movement earned it the name of "quick-beam"
in Anglo-Saxon, and the Lowland Scots name, "quakin' asp" (corrupted
into "quakin' ash") has, so far, survived the operations of School
Boards. Long may it do so! The same characteristic in this tree gave it
the Gaelic name of _crithean_ (creean) or _criothach_ (creeagh), "the
trembler," which may be recognised in such place-names as Creechan in
Dumfriesshire and, perhaps, Crieff, in Perthshire. Although in bulk and
stature one of the humbler members of the poplar family, the asp
exhibits in an extreme form a peculiarity common to all the
genus--namely, that of hanging the leaves vertically, instead of holding
them horizontally. The leaves are glandular on both surfaces, which may
be either the effect of or the reason for their assuming a position
protecting both surfaces from the direct rays of the sun. To secure this
position, the petiole, or foot stalk, of each leaf, being cylindrical in
most of its length, is suddenly flattened midway between the leaf and
the twig, as if it had been pinched while soft. This causes the leaf to
hang as described, and to quiver with the slightest breath of air.
The asp is a hardy mountaineer; its graceful foliage and _eau-de-Nile_
bark saves many a Highland hillside from dreariness, but it has long
ceased to have the economic importance it once had. By an Act of the
English Parliament (4 Henry V. c. 3), a penalty of 100 shillings was
imposed upon anyone who put aspen wood to any other purpose than the
making of arrows. Mrs. Hemans has woven into verse the mediæval myth
which taught men to reckon this pretty tree accursed:
Oh! a cause more deep,
More solemn far, the rustic doth assign
To the strange restlessness of those wan leaves.
The cross, he deems, the blessed cross whereon
The meek Redeemer bowed His head to death,
Was formed of aspen wood; and since that hour
Through all its race the pale tree hath sent down
A thrilling consciousness, a secret awe,
Making them tremulous, when not a breeze
Disturbs the airy thistle-down, or shakes
The light lines of the shining gossamer.
Gerard, writing in the sixteenth century, says, with scant gallantry,
that the asp "may also be called _tremble_ after the French name,
considering it is the matter whereof women's toongs were made, which
seldom cease wagging."
[Illustration: LOMBARDY POPLAR IN SUMMER]
[Illustration: LOMBARDY POPLAR IN WINTER]
Professor Sargent enumerates eleven species of poplar as indigenous to
North America, some of which, such as the Balsam poplar (_P.
balsamifera_), the Ontario poplar (_P. candicans_), and the Carolina
poplar (_P. angulata_), have risen to large dimensions in British
woodland; but to follow out these, and their constantly recurring
hybrids, would far exceed the limits of this paper.
There are many Asiatic species also, one of which (_P. euphratica_) we
are now taught to recognise as the "arabim" whereon the captive Jews
hung their harps (Psalm cxxxvii. 2). The weeping willow, named by
Linnæus _babylonica_, is not found in the valley of the Euphrates.
It is time that British planters should recognise the importance of the
more vigorous species of poplar as rapid timber-producers, thriving in
cold, wet ground where no other crop could be raised so successfully. A
useful example is set in this matter by French cultivators, who plant
more poplars than any other tree. Moreover, all the species are most
easily propagated and handled in planting. They should be grown from
cuttings; it is futile to attempt raising them from seed--a most
uncertain process, and unsatisfactory when it succeeds, cutting-grown
plants being far more vigorous than seedlings.
The Birch
Bentham and Hooker recognised only two species of birch as indigenous to
the British Isles--namely, _Betula alba_, the common birch, and _B.
nana_, an insignificant shrub which grows in the Scottish Highlands.
Messrs. Elwes and Henry, however, in their great work give specific rank
to each of the two forms of the common birch prevailing in this country.
It is certainly strange that the difference between them has not
received more attention from foresters, seeing that one is a far more
valuable tree than the other. Whether they be permanent species or
merely racial varieties matters not for practical purposes; but it
matters much that the better kind be planted where conditions are
favourable for it.
The commoner and less desirable of the two forms has been named _B.
pubescens_, owing to the young shoots being clothed with down, sometimes
so minute as to require a lens to show it. This and the habit of the
tree are the only constant marks of distinction from the other form,
which is named _B. verrucosa_, because the shoots, though shining and
perfectly free from down, are studded with minute _verrucæ_, or warts,
easily discernible by the naked eye. I have found in southern Norway,
where the two reputed species grow together, intermediate forms which
are no doubt natural hybrids.
The two species are usually quite different in habit, the common birch
(_B. pubescens_) never carrying the long pendulous branchlets which
distinguish the silver birch (_B. verrucosa_). Moreover, the common
birch does not usually attain the stature of the other, although Mr.
Elwes mentions having measured one at Malborough 90 feet high, with a
girth of 8 feet. This is the species which grows naturally over the
greater part of Scotland, especially in the west and north. The
distinctive downiness of the young twigs may have had its origin in the
humid atmosphere and abundant rainfall of the regions where it most
abounds. Geographically it enjoys a very wide range, extending farther
north than any other tree--as far as latitude 71° near the North
Cape--and reappearing in Iceland and southern Greenland, far within the
limit of floating ice. Eastward it extends as far as Kamschatka, but it
does not reach southward beyond the Alps, not being found in the
Pyrenees or the Apennines, whereas the silver birch reaches down to
Sicily.
Coming to the north-east of Scotland, to Strathspey, Deeside, and part
of the basin of the Moray Firth, one finds a change in the aspect of the
birch forest; for here, although the common birch still prevails on the
wetter parts, the silver birch is dominant on the drained land and hill
sides. It is there that the lady of the woods displays her true grace
and it is hard to say whether she is more lovely in summer, when she
waves her long green tresses in the breeze, or in winter, when the
slanting sunbeams glint on the snowy stem, and the drooping branchlets
appear like fine tracery against the sky. This is the true weeping birch
so highly prized by landscape gardeners, and this is the species that
should always be chosen for planting, provided the land is well drained,
for it cannot stand damp feet with the same impunity as its cousin. The
general rule is not difficult to remember that, whereas the common or
downy birch will grow on almost any soil that is not actual swamp, the
silver or weeping birch is very impatient of stagnant moisture.
Beautiful as are the birch woods of Strathspey (travellers to the North
must have been charmed with those on both sides of the railway near
Lochinsch Station), it must be confessed that the silver birch does not
attain its greatest perfection in Great Britain. Individual trees may be
found to compare pretty well with those in Continental woods; but the
general average is not so good. I have not seen the birch forests of the
Baltic provinces and Central Russia; those who have done so speak
enthusiastically of them; but it is from no want of loyalty to the Birks
of Aberfeldy that I have to admit that their bark has not the sheen nor
their growth the free grace of their kindred in French, German, and
Scandinavian forests.
[Illustration: BIRCH (_Betula alba verrucosa_) IN JUNE]
[Illustration: BIRCH (_Betula alba verrucosa_) IN DECEMBER]
Inseparably associated as the birch is with Scottish landscape, poets
and painters have never wearied of honouring it. The late David
MacWhirter got its beauty rather on the brain, and one turned rather
tired of what became a mannerism in his work. Hamilton of Bangour never
rang his quaintly iterative changes so tenderly as in his ballad, _The
Braes of Yarrow_, the tragedy of a maiden with two lovers. The lovers
fight, and one falls--
The comliest swain
That e'er pu'd birks on the braes o' Yarrow.
The survivor presses his court, trying in vain to persuade the girl to
leave Tweedside and come to his home beside Yarrow.
Sweet smells the birk, green grows, green grows the grass--
Yellow on Yarrow's braes the gowan;
Fair hangs the apple frae the rock,
Sweet the wave of Yarrow flowin'.
"Flows Yarrow sweet?" she argues with him--
Flows Yarrow sweet? as sweet, as sweet flows Tweed;
As green its grass, its gowan as yellow;
As sweet smells on its braes the birk,
The apple frae its rock as mellow.
The late Professor Veitch laid finger on the only blot in this fair
picture. Apples do not hang from rocks either in Tweedside or by Yarrow,
but rowan berries do. It is a pity that Hamilton yielded so far to
eighteenth century classicism as to introduce the conventional apple.
The line would surely have run more smoothly--
"Fair hangs the rowan frae the rock."
But I have wandered away from the birch. Economically, this tree has
hitherto been reckoned of indifferent value, though there is an
inexhaustible demand for bobbins. Clogmakers, also, will make
picturesque encampment among birches of suitable size, and pay a fair
price for working up the stems.
Of the well-nigh imperishable bark no use is made in this country,
except that chemists extract from it an antiseptic called pyrobetulin,
used also in the preparation of glass for engraving. But Scandinavian
farmers sheath their wooden houses with birch bark, which makes a
durable, waterproof covering, with a beautiful silvery appearance very
gratifying to eyes offended by the evil aspect of corrugated iron. In
Russia, also, a fragrant oil is distilled from birch-wood, whence Russia
leather derives its peculiar odour. Careful housewives should note that
there is no kindling equal to birch bark, which blazes up almost as
fiercely as celluloid.
Of late years, a new use has been found for birch, deserving attention
from owners of land whereon this tree grows naturally. The small
branches and spray are found serviceable in the preparation of steel
plates, the price given at present being about 46s. a ton. The trees
should be cut before the sap rises, else the bundles will lose weight in
drying. In dealing with a birch wood for this purpose, the crop may be
considered recurrent at short rotation; for numerous suckers arise from
the roots after the tree is felled and grow very rapidly. It is to be
noted with satisfaction that the well-nigh omnivorous rabbit cannot
digest the young growths of birch; at least, it does not devour them
wholesale.
The birch is very impatient of the shade of other trees. In its turn,
although its delicate foliage might not be supposed to stop much light,
its shade is very injurious to all other deciduous trees except the
beech; a quality which causes one to wonder that such an experienced
observer as P. J. Selby should have recommended it as a nurse for
oak.[12] It is liable to be disfigured by the morbid growths popularly
known as "witch's brooms." Authorities differ as to the cause of these
fascinated bundles of twigs, some attributing them to the action of a
fungus, _Exoascus betulinus_, others to the irritation brought about by
a gall-mite (_Eriophes rudis_) attacking the buds. Probably both are
contributory agents.
The Gaelic for birch is _beith_ (pronounced "bey"), and may be
recognised in numberless Scottish place-names, such as Drumbae,
Auchenvey, Largvey, etc. The derivative _beitheach_ (pronounced
"beyoch"), signifying a birch wood, appears as Beoch in Ayrshire,
Galloway, and Dumfriesshire.
Of exotic birches suitable for cultivation in the United Kingdom, there
is a very complete collection in Kew Gardens. Among the North American
species the black or cherry birch (_Betula lenta_) probably produces the
best timber, but the most ornamental is the paper birch (_B.
papyrifera_). The Japanese (_B._ _maximowicsii_) seems to promise
better bulk than any other as a forest tree in this country.
[Illustration: WILLOW BY THE STREAM]
The Willows
"I offered him my company to a willow-tree, either to make him a
garland, as being forsaken, or to bind him up a rod, as being
worthy to be whipped."--_Much Ado About Nothing_, Act ii. sc. i.
"Willows whiten, aspens quiver,
Little breezes dusk and shiver
Through the wave that runs for ever
By the island in the river
Flowing down to Camelot."
_The Lady of Shallot._
A certain botanist of distinction being consulted by an amateur about
some variety of willow exclaimed: "Pray, don't tempt me among the
willows; that way lies madness!" They are, indeed, a most complex
family, consisting of no fewer than one hundred and sixty recognised
species, besides those chance hybrids which, being not only
wind-fertilised, but dioecious (that is, the male and female
inflorescence is borne on separate trees), they are so prone to produce.
Bentham and Hooker admitted fifteen species as indigenous to the United
Kingdom, ranging from _Salix herbacea_, dwarfest of British shrubs,
humbly crouching on bleak mountain crests and seldom rearing its fairy
branchlets to a greater height than a couple of inches, to the massive
white willow (_S. alba_), which may tower to the height of nearly 100
feet.
British foresters have not hitherto turned the capabilities of the
better kinds of willow to such account as might be done, for, except in
the osier industry and for the manufacture of cricket bats, willows are
scarcely ever cultivated for profit. When they are planted at all they
are generally shoved into some piece of sour, swampy ground, fit for
nothing else; and the fact that they will actually flourish in such
places is taken as evidence that they prefer them. But the better
willows appreciate a kindly soil as much as any other tree, and it is
only on wholesome, but moist, land that they develop their proper
qualities.
By far the most valuable willow in the present condition of the timber
market is the blue willow, which some botanists distinguish as a species
under the name of _Salix coerulea_, but which is more generally deemed
to be a hybrid between the white willow (_S. alba_) and the crack willow
(_S. fragilis_). It is easily distinguished from both its reputed
ancestors; first, by its habit, which is far more erect than that of the
others, all the branches ascending without any tendency to spread or
droop; second, by its leaves, which are not nearly so downy as those of
the white willow, and of thinner texture, so that, when one is held up
against the light the tertiary venation may be seen through a lens to be
translucent; and, third, by the bark, which is quite different from the
rugged covering of the crack willow, and much smoother than that of the
white willow. The fissures or seams in the bark are straight and set
close together, enabling one to distinguish the blue willow from all
other kinds at all seasons. The general tone of the foliage is silvery
blue, instead of the silvery grey of the white willow.
The peculiar value of this willow consists in its producing the only
wood suitable for first-class cricket bats. Golf has threatened, but has
not yet undermined, the supremacy of cricket; and so long as the English
national game holds its own, so long will good samples of the blue
willow command a high price. It was in the eastern counties of England
that this tree originated, and it is thence that dealers continue
exclusively to draw their supplies, being willing to pay what might be
thought extravagant prices for the right article. Thus, Elwes records
how, in January, 1912, eleven willows were sold in Hertfordshire at
fourteen years of age for £81, or about 13s. per cubic foot. These trees
had made amazingly rapid growth, ranging from 50 to 60 feet high; but
the quality of the wood does not seem to deteriorate with age and bulk,
for in 1888 a blue willow, fifty-three years old, was sold at Boreham,
in Essex, and manufactured into 1179 cricket bats. This tree measured
101 feet high, with a girth of 16 feet 3 inches. From the same estate
another blue willow was sold in 1911 for £70. The dimensions have not
been recorded, but the purchaser estimated the price of the serviceable
wood at about £1 per cubic foot. Even more remarkable seems the
experience communicated by Mr. J. Barker of Pishiobury, Sawbridgeworth,
to the _Gardeners' Chronicle_ in 1906. He states that a parcel of land
was bought for £50 in 1889 and planted with willows, which were sold in
1905 for £2,000.
Such results as these have no parallel in British forestry; and it may
be deemed strange that more attention has not been given to the
cultivation of the blue willow. Even in Herts and Essex few of those who
grow it for the market are at pains to clear the stems of branches to a
greater height than 12 or 15 feet. There appears to be nothing
exclusively in the dry climate of East Anglia essential to the
development of good "bat" qualities; for Mr. J. A. Campbell of Ardluaine
(to whom I owe thanks for some sets of this willow) has received a most
favourable report on the wood of trees grown by him in the humid
atmosphere of Lochgilphead. In short, the blue willow is as tolerant of
conditions of soil and climate as any other native willow, and could
probably be grown at a profit in any county of the United Kingdom where
shelter from violent winds can be had; but, of course, extended sources
of supply would naturally cause a fall in the present exorbitant prices.
The approved method of propagating the blue willow is by large "sets"
from 10 to 20 feet long, cut from the branches of trees that have been
felled. These have to be sharpened at the butt and firmly set in holes
3 feet deep, formed by driving in and removing a stake. Like the poplar,
the willow imperatively demands light, and to obtain a fine quality of
timber, the growth must be rapid. Being so impatient of shade, these
trees must not be subjected to planting in close canopy, as recommended
for coniferous and other trees. The "sets," therefore, should be planted
fully 30 feet apart; and to secure a clean hole, side buds must be
rubbed off the saplings, and careful pruning applied in later years.
It must not be supposed that the supply of cricket bats exhausts the
purposes to which the wood of the blue willow may be applied. This
variety should be planted in preference to any other, because it exceeds
all others in rapidity of growth, and produces timber of fine quality
faster than any other tree that can be grown in the British Isles. But
the white willow (_S. alba_), more commonly known as the Huntingdon
willow, also yields a rapid return of light, tough wood, very durable,
and suitable for flooring, couples, cart and waggon bodies. Dr. Henry
measured two Huntingdon willows near Palnure, Kirkcudbright, in 1904,
and found them respectively 86 feet high by 10 feet 8 inches in girth,
and 82 feet by 12 feet 9 inches. But the largest willow of this species
now growing in Scotland is probably one at Coodham, near Kilmarnock,
which girthed 17 feet 1 inch in 1904.
Leaving aside the kinds of willow cultivated for osiers (a most
profitable industry), the only other native species worthy of
consideration as a timber tree is the crack willow (_S. fragilis_); so
called because of the fragility of the branchlets in spring. A
remarkably vigorous variety of the species, popularly known as the
Bedford willow, and scientifically as _S. Russelliana_, appears to have
originated about the year 1800, probably as a hybrid. A large specimen
growing in Messrs. Samson's nursery at Kilmarnock was blown down in
1911. It was 80 feet high and 16 feet in girth.
Both the crack willow and the Bedford willow may be easily distinguished
from the white or Huntingdon willow by their rugged bark, seamed with
broad and deep grooves, and by their foliage, which is green and
shining, each leaf ending in a long point bent to one side. The timber
is inferior in quality to that of the white and blue willows;
nevertheless, it is recorded in Lowe's _Agricultural Survey of Notts_
(p. 118) that a plantation of Bedford willows "yielded at eight years'
growth poles which realised a net profit of £214 per acre." It is not
unlikely, considering the confusion which prevails among species and
varieties, that these were blue, not Bedford, willows.
The lugubrious associations with which poets have invested the willow
probably may be traced to the English translation of Psalm cxxxvii. 2;
but, as noted on page 81, no willow grows on the banks of the Euphrates,
and it was a species of poplar whereon the captive Jews hung their
harps. Linnæus may be excused, in consideration of the difficulties of
travel in the eighteenth century, for having named the weeping willow
_Salix babylonica_, though that species is only to be found wild in
China; but it is an instance of the mischievous practice of one writer
copying the statements of another that in Kirkby's _Trees_ we read that
the weeping willow "grows abundantly on the banks of the Euphrates and
other parts of Asia, as in Palestine, and also in North Africa."
The name "willow" speaks to us of a time when our Anglo-Saxon forbears
dwelt in wattled houses. They spoke of the tree as _welig_ and also as
_widig_ (whence our "withy"), the root-meaning being pliancy. Another
old English name for the tree was "sallow," which in the north has been
shortened into "saugh," a term associated with one of the darkest
episodes in the somewhat murky annals of the Stuart dynasty; for it was
at Sauchieburn near Stirling that James, Duke of Rothesay, aged fifteen
years, was brought by the rebel lords to do battle with his father James
III. on 11th June, 1488. King James, flying from the field, was done to
death; and, in contrition, his son wore an iron chain round his waist
till he, too, fell as James IV. at Flodden, twenty-five years later.
The Gaelic for willow is _saileach_, whence innumerable place-names in
Scotland and Ireland, such as Barnsallie, Barsalloch, Sallachy,
Lisnasillagh, etc.
The Hornbeam
The hornbeam (_Carpinus betulus_) belongs to the birch family and the
beech belongs to the oak family, so they are far from being nearly akin;
nevertheless, the hornbeam and the beech have certain qualities
singularly similar in the two species.
First, the hornbeam imitates the foliage of the beech so closely that
when either of them is dressed as a hedge plant (a purpose for which
both are peculiarly suitable) it requires close inspection to determine
which tree it is. Second, except the elder, the beech and the
hornbeam are the only shade-bearers among our indigenous deciduous
hardwoods--that is, the only broad-leaved trees--that will flourish
under the shade and drip of other forest growths, thereby proving most
useful for under-planting. Third, as firewood there is none equal to
either beech or hornbeam, both of them excelling all other woods in the
amount of heat they discharge in combustion.
[Illustration: FRUIT OF HORNBEAM (_Carpinus betulus_)]