Part 5

The life period of the sycamore is a long one, probably three times that of the beech and equal to that of the oak. At Truns, in the Swiss Oberland, a great sycamore, already in ruin, was destroyed by a storm in 1870. As it was under this tree that the Grey League, originators of the canton of Grisons, took the oath in 1424, it can scarcely have been less than 600 years old when it ceased to exist. Mr. Elwes gives the dimensions of another mighty sycamore in Switzerland, growing at an elevation of more than 4000 feet in the canton of Unterwalden, which must be coeval with the tree of the Grey League. It measures 29 feet in circumference at 5 feet from the ground. We cannot quite equal that in Scotland, although in that country and northern England there are some enormous sycamores. Behind the Birnam Hotel stand two very large trees, an oak and a sycamore. The oak, lesser of the two, is shown to visitors as the last survivor of that forest whereof it was said

Macbeth shall never vanquished be Until great Birnam wood to high Dunsinane hill Shall come against him.

The other is a giant sycamore, reported in Hunter's _Woods and Forests of Perthshire_ (1883) to be one thousand years old, which, of course, is impossible. I measured the girth of this great tree in 1903, and made it 19 feet 8 inches at 5 feet from the ground. It was not until long after that I found that Hunter had given exactly the same measurement twenty years earlier. This girth is exceeded by one at Castle Menzies, which, in 1904, gave 20 feet 4 inches. The loftiest sycamore reported in Scotland is also in Perthshire, at Blair Drummond. This tree Dr. Henry ascertained to be 108 feet high, with a girth of 10 feet.

At Kippenross, also in Perthshire, there remain fragments of a sycamore destroyed by lightning in 1860. It was known in the seventeenth century as "the Muckle Tree o' Kippenross," and was estimated in 1821 to contain 875 cubic feet of timber.

It would be vain to attempt within reasonable limits of space to give a catalogue of the notable sycamores in Great Britain. Most of the finest specimens are in Scotland; for no tree can be planted in our northern land with greater security of success; it fears neither severe frost nor reasonable wind exposure; but it insists upon well-drained soil. In damp, low-lying ground it may appear to flourish; but in such a situation it is sure to prove "boss" (to use a term in Scottish forestry) or hollow at the heart when ready for the axe. In England there are many sycamores of 100 feet and upwards; but this tree has become much more closely identified with the landscape of the northern counties than with that of the south.

As a forest tree, the sycamore has been treated with unmerited neglect by British planters; though it is not singular in that respect, so improvidently have we accustomed ourselves to rely upon foreign supplies. We ought to bestow more care upon our sycamores, because not only is it a tree that rapidly re-establishes itself by seed and is practically immune from disease, but it produces timber which, when of sufficient size, commands a higher price than any other British-grown wood. That size is not less than 18 inches quarter girth, representing sixty to eighty years' growth, and from that size up to any dimensions, provided that the bole is straight, clean-grown and free of knots. The main purpose for which such stems are in demand is for making large rollers used in calico and wallpaper printing, in washing machines and cotton dyeing. A few years ago I was shown a single sycamore growing at Makerstoun on Tweedside for which the owner had been offered, and refused, £50. The wood is also in good request for railway carriage panelling, furniture, dairy utensils, etc.

As an ornamental tree it must be owned that the sycamore does not take high rank, owing to the monotonous tone assumed by its massive foliage after the flush of spring has passed. Nor does it usually compound for this by splendour of autumnal colour, as so many of the maple family do. Indeed, this is one of the qualities of its near kindred which the sycamore has discarded in order, it would almost seem, to simulate the plane more perfectly and to justify its appellation of "the false plane"; for the foliage of the plane falls like that of the sycamore without any dying brilliancy. It is true, however, that old sycamores, when sheltered from sea winds, do sometimes assume bright tones of yellow and orange in autumn. At Keir, in Perthshire, a row of aged trees of this species surprised me by their brilliancy in November, 1913.

Although, as I have said, the sycamore is remarkably free from disease and from serious fungoid or insect attacks, it is the host of a parasitic fungus which seldom fails to make its presence apparent, though without perceptibly affecting the growth or health of the tree. Readers must be very familiar with the circular black spots which appear on the leaves about midsummer and continue till they fall. It is not a few leaves or a few trees here and there that are so affected, but all the leaves on large trees and on every tree in the wood. The difficulty is to find a leaf without these black spots; so that people have come to regard them as part of the regular colour scheme of the foliage. Nevertheless, each of these blots is a colony of the parasitic fungus, _Rhytisma_, whereof the life-history is still subject for investigation. It is not evident how the colonies are regularly distributed, each clear of the other, all over the leaves of a lofty tree, nor how, seeing that they fall to the ground with the leaves in autumn, the fungus manages to get access in the following summer to the loftiest branches. It is lucky that, being so widely distributed and existing in such incalculable numbers, these colonies do not appreciably interfere with the natural functions of the sycamore.

The only native species of maple in Britain is the Field Maple (_Acer campestre_), which does not extend naturally into either Scotland or Ireland, though it grows freely in both these countries when planted in either of these countries. It is a very ancient element in the woodland of south Britain, its remains having been identified in pre-glacial beds in Suffolk. It has no qualities to recommend it for ornamental planting, and the timber, once highly prized by British cabinetmakers, has been ousted from the home-market by imported foreign woods. When the Rev. William Gilpin, author of a well-known work on _Forest Scenery_, died in 1804, he was buried, it is said, at the foot of a field maple growing in his own churchyard at Boldre, in the New Forest. Strutt gave a figure of this tree which he described as the largest of the species in England; but he gives the height as only 45 feet, whereas Elwes records several from 60 to 70 feet high.

A far more desirable tree than the field maple is the Norway maple (_A. platanoides_, Linn.). The title "Norway" no more indicates its natural range than the term "Scots" does that of _Pinus sylvestris_, for this maple is found in most European countries and as far east as Persia and the Caucasus. It is a beautiful tree, especially in autumn, when its foliage takes on brilliant red and yellow hues; but it requires attention during the first twenty or thirty years of growth, in order to check its disposition to a straggling branchy habit. If that be stopped by timely pruning, the Norway maple grows straight and free, attaining, under favourable conditions, a height of 80 to 90 feet. Its timber has not the ornamental character of that of field maple, but is said to be of similar quality to that of sycamore. The petioles or leaf-stalks of this species contain a milky juice, whereby the tree may be distinguished from all other members of the genus.

Now, whereas botanists enumerate no fewer than one hundred and ten species of maple, natives of Europe, Asia and America, it would be impossible within the limits of this modest volume to discuss even the most desirable of the genus. Among the North American species there are several that grow to splendid dimensions in their native forest. One of the most distinct is the red maple (_A. rubrum_), a beautiful object in spring when it bears flowers profusely, which, in some varieties, are of a charming red colour. There are a few specimens in England of the well-known sugar maple (_A. saccharum_), but it seldom thrives in this country, though it has been frequently tried since its introduction, according to Loudon, in 1735.

The Plane

Among Scottish foresters the name "plane-tree" has come to signify the sycamore; but the sycamore is a kind of maple, whereas the term "plane" is rightly appropriated to _Platanus_, whereof there are four species, constituting the natural order of _Platanaceæ_. Of these four species, three are natives of North America; and forasmuch as none of them has proved amenable to cultivation in Europe, they may be dismissed with the remark that one of them, the button-wood (_P. occidentalis_), attains enormous proportions in its native forests, rising to a height of 170 feet, and with a girth (recorded by Michaux) of 47 feet.

The fourth species (_P. orientalis_) ranks among the noblest hardwoods of temperate Europe and Asia. Clear among memories of many sylvan scenes stand a pair of giant planes on the flank of Mount Olympus, in the leafless branches of which on a bright January morning a pair of white-tailed eagles monopolised the attention which I was intended by my Turkish host to devote to woodcocks in the copse below. Those who have sailed along the Dalmatian coast will doubtless remember the harbour of Gravosa, and the solitary plane that casts such a grateful shade across the quay. But one need not go to the Continent for giant planes. In our day it is one of the trees most commonly planted in the southern counties for shade and ornament, and has no equal for the smoke-laden atmosphere of London. It may be that it was one of Evelyn's seedlings that Bishop Gunning planted in his Garden at Ely between 1674 and 1684. This tree in 1903 was 104 feet high, with a girth of 20½ feet. Messrs. Elwes and Henry give a photograph of it in their _Trees of Great Britain and Ireland_, and consider it to be the largest specimen in our islands of the cut-leaved variety.

Turner, writing in 1562, mentions "two very young trees" growing in England, which indicates the middle of the sixteenth century as the period of its introduction. A hundred years later, Evelyn says he has raised from seed--

"_Platanus_, that so beautiful and precious tree so doated on by Xerxes that Ælian and other authors tell us he made halt and stop'd his prodigious army of seventeen hundred thousand soldiers to admire the pulchritude and procerity of one of these goodly trees, and became so fond of it that he cover'd it with gold gemms, necklaces, scarfs and bracelets, and infinite riches."

The maple-leaved variety, usually known as the London plane, is the sort most commonly planted in England, and rightly so, for it is more vigorous than the other. Probably the tallest in England grows at Woolbeding, in Sussex; it was 110 feet high in 1903, with a girth of 10 feet, and a clean bole of 30 feet. It would be needless to enumerate the fine planes in and near London; one has only to look at the groups beside the Admiralty and in Berkeley Square to realise how it thrives in an atmosphere pernicious to nearly all other forest growths. Fifty or sixty years hence the avenue of planes planted not long since along the Mall will be one of the sights of Europe. The skilful way in which they are being trained each to a single leader gives them a stiff, ungraceful appearance at present; but this treatment is a bit of true arboriculture, carried out in the teeth of bitter criticism. "Bairns and fules shouldna see things half dune."

It is the absence of the conditions specially favourable to the growth of the plane in London and the south that makes it unsuitable for planting in the North of England and in Scotland. It is native to a region of scorching summers; in London the sun's heat is reflected from buildings and streets in a manner most acceptable to it. It will stand any amount of frost it may encounter in Scotland; but it pines for want of summer heat, witness the unhappy condition of those which have been planted experimentally along the west end of Princes Street, Edinburgh. I do not know of a single plane of more than mediocre stature north of the Tweed.

The plane is nearly as late in leafing as the ash and the walnut, thereby escaping the cruel frosts so characteristic of British spring; but unlike the ash, it retains its foliage into very late autumn. Pliny described an evergreen plane growing in Crete; but after the botanist Tournefort (1656-1708) had searched the island in vain for it, this was relegated to the category of myths. Howbeit, tardy justice was done to Pliny as the prince of field naturalists, when in 1865 Captain Spratt, R.N., was shown two young plane trees, retaining their leaves throughout the winter, which had sprung from the root of a very large tree that had been felled. He also heard of two others.

The Oriental plane has not been long enough established with us to give an estimate of its longevity in Britain. In the Mediterranean region it attains a vast age. Only a hollow stump remains of one at Vostiza, in the Gulf of Lepanto, which in 1842 was about 130 feet high and 37 feet 4 inches in girth, and was believed to be the tree described by Pausanias when writing his description of Greece in the second century after Christ. Neither have we learnt to make much use of the timber so plentifully produced by the plane, though it is said to be second to none for the bodies of carriages.

In antiquity of descent the plane tree has few, if any, superiors among broad-leaved trees, its remains having been recovered from the Cretaceous beds of North America, besides numerous species recovered from Miocene and Tertiary strata, in Northern Europe, whence they were expelled when that region became icebound.

The London planes have been accused of being chief agents in inflicting influenza, bronchitis and catarrh upon the inhabitants of the metropolis. It has been seriously affirmed that when the seed-vessels of the plane break up in dry spring weather, the air is filled with minute spicules which act as an irritant upon human throats and noses. It may be so; but before condemning the trees, without which London would indeed be desolate, it would be well to ascertain first whether the ailments referred to are more prevalent in London during the months when the plane tree is shedding its dry fruit than they are at other times of the year; and second, whether they are more prevalent in London, where there is wealth of planes, than they are in cities where there are no planes, as Edinburgh, Glasgow, Liverpool, Newcastle, etc. Unless this can be shown to be the case, it is difficult to reconcile the fact that London has the lowest death-rate among the cities of the United Kingdom with any mischief arising from the luxuriance of these beautiful trees.

The Horse Chestnut

In one respect the horse chestnut (_Æsculus hippocastanum_) may be reckoned among the most remarkable trees of British woodland, inasmuch as, although it has been found in a wild state only here and there among the mountains of Greece and Albania, where it enjoys a climate widely dissimilar from that of Western Europe, it has a constitution so cosmopolitan as to become thoroughly at home in all parts of our country. It thrives as vigorously on the dry chalk soil of Hertfordshire as on the soaked hillsides of Perthshire, and, given reasonable shelter from violent winds, produces its magnificent foliage and flowers as freely near sea level as it does at Invercauld in Aberdeenshire, where there is, or was not long ago, a fair specimen growing at an elevation of 1,110 feet, not far short of the practical limit of tree growth in Scotland. In 1864 this horse chestnut was 8 feet 7 inches in girth, and was believed to have been planted in the year 1687; therefore, if it still stands, it is now 226 years old.

Another sign of the adaptability of the horse chestnut to British environment is the freedom with which it ripens its large fruit and reproduces itself from self-sown seed wherever it gets a chance. The facility with which it does so has caused this tree to be deemed indigenous in many parts of Europe and Asia where it certainly is not a native, but where it has been planted originally on account of its beauty. Further confusion has arisen from the botanists Linnæus and De Candolle having failed to distinguish the Indian horse chestnut (_Æ. indica_) from the Greek species, and having assigned Northern Asia as the native region of the latter.

It would not be difficult to mention many individual horse chestnuts in the British Isles exceeding 100 feet in height; probably this tree, if subjected to forest conditions, would grow far loftier than that; but, as it is usually planted exclusively for ornament, it is most often found standing isolated, thereby receiving encouragement to develop enormous side branches and to grow in breadth and bulk rather than in height. Such is the character of a great horse chestnut standing in a group near Moncrieff House, Perthshire. In 1883 this tree measured no less than 19 feet in girth at 5 feet from the ground; but at 10 feet it divides into three huge limbs, each girthing 10 feet, and covers a space nearly 100 yards in circumference. The soil in this district is cool and the climate humid, very different from the conditions at Ashridge in Hertfordshire, where the soil is chalky and hot; yet there is in that fine park a horse chestnut even more massive than the Moncrieff House specimen, being about 80 feet high, and measuring 20 feet in girth. Probably the loftiest horse chestnut in Britain, perhaps in the world, is one at Petworth, in Sussex, which, having been drawn up in close forest, now measures between 115 and 120 feet in height.

It is a pity that this noble tree does not more often receive encouragement to upward growth, seeing that if the surrounding trees are cleared away judiciously, that is not too suddenly, after the horse chestnut has reached a good height, it then feathers down in the most charming manner. It is very seldom that, without discipline of this kind, it will put its energy into height, and attain the fine proportions of a specimen at Biel, in East Lothian. In 1884 this grand tree, probably the loftiest in Scotland, measured 102 feet in height, with a clean bole of 40 feet. It is worth any amount of trouble to secure this character in the horse chestnut, which is an inveterate spreader if allowed licence; and the tendency may be checked by knocking side buds off the stem in the sapling stage, and timely pruning as the tree goes on to maturity.

As an avenue tree, the horse chestnut has few, if any, superiors. Perhaps the finest examples in Scotland of this manner of planting it are to be seen at Gilmerton, in East Lothian, and Drummond Castle, in Perthshire; while in England the splendid double avenue at Bushey Park, Middlesex, has long been famous, "Chestnut Sunday" being a noted festival for Londoners when the trees are in full bloom. The horse chestnut, however, is not a long-lived tree, and cannot be reckoned upon to survive beyond 250 years. The Bushey Park chestnuts are failing fast, many having died already and been replaced by saplings.

Talking of avenues, it is worth while to note a calamity described by Mr. Hutchison of Carlowrie in the Transactions of the Highland and Agricultural Society for 1884. He states there that in 1867 an avenue of horse chestnuts was planted as an approach to the cemetery of Wimborne, Dorsetshire, the trees being set 25 feet apart in the rows. In 1875 it was thought to improve the avenue by planting yews in the intervals between the chestnuts, which had this unfortunate result, that the chestnuts, which had previously thriven finely, all pined away and died.

It is on record that the horse chestnut was first brought to France in 1615, and probably found its way into England about the same time. It seems that it was expected to rank with walnuts and Spanish chestnuts as a fruit tree, a notion which was speedily dispelled. John Evelyn, however, with a right taste for sylvan beauty, early discerned its decorative merit, writing about it in 1663 as follows:

"In the meantime I wish we did more universally propagate the horse chestnut, which being increased from layers, grows into a goodly standard, and bears a glorious flower, even in our cold country. This tree is now all the mode for the avenues to their country places in France."

Travellers in that fair land will remember with pleasure the fine use still made of this tree beside some of the high roads. Between Tours and Blois the wayside has been planted with a chestnut unknown to Evelyn, for it did not exist anywhere in his day. This is the red horse chestnut (_Æsculus carnea_), which seems to have originated in Germany about the beginning of the nineteenth century, and is believed to be a hybrid between _Æ. hippocastanum_ and the North American shrub _Æ. pavia_. It is a most beautiful tree, the flowers being of a delightful shade of bright carmine. We are told not to expect it to attain the stature of the common horse chestnut, so it would be well, in designing an avenue, not to mix the red and the white with a view to matching them in height; but the red hybrid has already risen to 50 feet high at Barton in Sussex, and I entertain an idea that this tree may develop into larger proportions than is expected of it, when planted in good soil and favouring shelter. At all events, some which I planted about thirty years ago are now quite as large as common horse chestnuts of the same age.

Mr. Elwes recommends the horse chestnut for planting in towns, remarking that "next to the plane it is one of the best trees we have for this purpose, and does not seem to suffer much from smoke." I regret that I am unable to endorse this view. It is true that in towns of moderate size, and in country villages, horse chestnuts may be planted with excellent effect. I know of few more charming sights than is presented by the group of these trees in the high street of Esher when they are in flower; but in London horse chestnuts prove a lamentable failure. Living as I used to do in the neighbourhood of Sloane Street, it was a distress to me each year to watch the stunted, round-headed chestnuts in the gardens at the lower part of that thoroughfare, and in Eaton Square, unfolding their delicate fingers only to have them parched and blackened by the ruthless drought and dirt of the Metropolis.

As a timber producer, the horse chestnut cannot be assigned high rank. There is no lack of quantity, for the tree increases very rapidly in bulk, but in quality the wood is soft, weak, and very perishable. Moreover, it is almost useless as fuel, and probably the only economic purpose to which it could be applied profitably is the production of wood-pulp and celluloid.