The Trees of Great Britain & Ireland/Volume 1/Thuya

by Henry John Elwes and Augustine Henry

 

THUYA

 

Thuya,^[1] Linnæus, Gen. Pl. 378 (1737); R. Brown, Trans. Edin. Bot. Soc. ix. 358 (1868); Bentham et Hooker, Gen. Pl. iii. 426 (ex parte) (1880); Masters, Jour. Linn. Soc. (Bot.) xxx. 19 (1893).

Biota, Endlicher, Syn. Conif., 47 (1847).

 

Evergreen trees of pyramidal habit and aromatic odour, belonging to the tribe Cupressineæ of the order Coniferæ. Branches spreading and much ramified, terminating in so-called "branch-systems," which are flattened in one plane and are 2-, 3-, or 4-pinnately divided, their primary and other axes being densely clothed with scale-like leaves. These branch-systems^[2] when they fall are cast off as a whole, the leaves not falling separately. The leaves, which are minute, are more or less coalesced with the axes, on which they stand in 4 ranks in 2 decussate pairs, those of the lateral ranks being conduplicate or boat-shaped, those placed dorsally and ventrally being flattened. In the seedling stage and certain horticultural varieties,^[3] the foliage is different, the leaves being acicular, spreading, and uniform; all 4 ranks in this case are alike.

Flowers monœcious, all solitary and terminal on the ultimate short branchlets of the preceding year, the male and female flowers on different branchlets, the former on the branchlets near the base of the shoot, the latter on those near its summit. Male flowers cylindrical or globular, consisting of 3 to 6 pairs of stamens placed decussately on an axis, each with an orbicular connective bearing 2 to 4 pollen sacs. Female flowers minute cones, composed of opposite scales in which no distinction of ovular scale and bract is visible, continuous in series with the leaves at the end of the branchlet, 2 to 4 pairs in Biota, 4 to 6 pairs in Euthuya, mucronate at the apex, some sterile, the others fertile and bearing 2 to 3 ovules.

Cones solitary, ultimately deflected, except in Biota, in which they retain the erect position, oblong, ovoid, or almost globose, composed of 3 to 6 pairs of decussate scales, which are not peltate, some fertile, the others sterile, the uppermost often united together. Seeds 2 to 3 on each fertile scale. Cotyledons 2.

The genus Thuya, as understood here, does not include Chamæcyparis and Thujopsis, which were united with it by Bentham and Hooker. So limited, it comprises 5 species, and is divided into the two following sections:—

I. Euthuya. Cones with thin, coriaceous mucronulate scales, those of the 2 or 3 middle ranks being fertile. Seed thin, with lateral wings and a minute hilum. This section comprises 4 species. Thuya occidentalis and Thuya plicata of North America, Thuya sutchuenensis of central China, and Thuya japonica of Japan.

II. Biota. Cones with thickened, conspicuously umbonate scales, which are fleshy when young, almost ligneous when ripe; those of the lowest two ranks fertile. Seed thick, without wings, the hilum being large and oblong. This section includes one species, Thuya orientalis of north China.

The Thuyas resemble considerably in foliage and habit the flat-leaved cypresses. The latter are best distinguished by their fruit, which consists of peltate scales fitting closely by their edges. In a subsequent part, the peculiarities, as regards the branch systems and leaves, of these cypresses (Cupressus Lawsoniana, nootkatensis, thyoides, obtusa, and pisifera) will be described, and may then be compared with those now given below for the four species of Thuya in cultivation.

In the discrimination of the Thuyas, in addition to the characters shown by the bark, mode of branching, and fruit, the primary and secondary axes of the branchsystems give good marks of distinction. These axes are markedly flattened in Thuya occidentalis, terete in the other species. In Thuya orientalis the branch-systems stand in vertical planes, the inner edges of which are directed towards the stem of the tree. In ordinary forms of the other three species they are arranged in horizontal planes. The leaves on the main axes in each species differ as follows: —

1. Thuya plicata:^[4] widely spaced, long, ending in long, fine, free points, which are parallel to the axis; glands inconspicuous or absent. Under surface of the foliage usually marked with white streaks.

2. Thuya japonica: placed closely together, shoots ending in short, rigid, thick, triangular points, directed outwards at an acute angle; glands absent. Under surface of the foliage conspicuously marked with broad white streaks.

3. Thuya occidentalis: widely spaced, ending in long, fine points, which are parallel to the axis; glands raised, large and conspicuous on the flat leaves. Under surface of the foliage pale green; white streaks inconspicuous or absent.

4. Thuya orientalis: widely spaced, ending in short triangular free points, which are not rigid, and are directed slightly outwards at an acute angle: flat leaves marked by longitudinal glandular depressions. Under surface of the foliage pale green, without white streaks.

Thuya sutchuenensis, Franchet,^[5] is a small tree occurring in north-east Szechuan in central China, where it was discovered by Pere Farges growing at an altitude of 1400 feet. The branchlets are much flattened, thin in texture, and practically glandless. Cones composed of 8 obovate scales, the apices of which are slightly thickened. This species has not been introduced into cultivation.

 

 

THUYA PLICATA, Giant Thuya

 

Thuya plicata, D. Don in Lambert, Pinus, ed. 1, ii. 19 (1824); Masters, Gard. Chron. xxi. 214; figs. 69, 70, 71 (1897); Sudworth, Check List Forest Trees U.S. 31 (1898); Sargent, Manual Trees N. America, 75 (1905).

Thuya gigantea, Nuttall, Jour. Philad. Acad. vii. 52 (1834); Sargent, Silva N. America, x. 129, t. 533 (1896); Kent, in Veitch's Man. Coniferæ, 239 (1900).

Thuya Menziesii, Douglas, ex Carrière, Traité Gén. Conif. 107 (1867).

Thuya Lobbi, Hort.

Thuya Craigiana, Hort. [non A. Murray, Bot. Exped. Oregon, 2 (1853)].

 

A lofty tree, attaining a height of 200 feet, with a trunk remarkably conical, the base being broad and buttressed, sometimes girthing as much as 40 to 50 feet near the ground.

Bark of the trunk Assuring longitudinally in narrow thick plates, which scale off, leaving exposed the reddish brown cortex beneath. On the branches, the bark only begins to scale when they become old and thick. Branches horizontal, ascending towards their ends, forming in England a dense, narrow, pyramidal tree, usually clothed to the base.

The 3-4 pinnate branch-systems, disposed in horizontal planes, have their main axes terete and covered with long leaves ending in acute points which keep parallel to the axes. The glands on these leaves are inconspicuous or absent. On the ultimate axes the leaves are smaller, the flat ones scarcely glandular, and ending in mucronate points; the lateral ones keeled on the back, slightly curved, and ending in sharp cartilaginous points. On the lower surface of most branchlets the foliage is streaked with white, some branchlets usually remaining uniformly green.

The male flowers are dark red in colour, cylindrical, and composed of about 6 decussate pairs of stamens.

The cones when ripe do not remain erect, but are deflected out of the plane of the branchlets. They are oblong, light brown in colour, and composed of 5 to 6 pairs of scales, of which the 2nd, 3rd, and 4th pairs are larger than the others, and fertile. The scales are oval or spathulate, with a rounded apex, from immediately below which externally a small deltoid process is given off. The seeds, 2 or 3 on each fertile scale, are brown in colour, two-thirds the length of the scale, and surrounded laterally by a scarious wing, which is deeply notched at its summit.

Seedling.^[6]—The 2 cotyledons are linear, flat, acute at the apex, and slightly tapering towards the base, supported on a terete caulicle, about ³⁄₅ inch long, which ends in a long brown flexuose primary root giving off a few fibres. The stem, terete and smooth near the base, becomes ridged above by the decunent leaf-bases. The first 4 true leaves are in opposite pairs, decussate with the cotyledons. Above these the stem gives off a number of whorls or pseudo-whorls of longer (½ inch) sharply pointed leaves, dark green above and pale beneath, with markedly decurrent bases. After a few of these whorls lateral branches are given off, which sometimes bear a few acicular leaves at their bases. The lateral branches ramify and approach in character those of the adult plant, as the leaves are arranged decussately in 4 ranks. These leaves are variable, being acicular and loosely imbricated, or scale-like and closely imbricate. The branches are ascending, horizontal, or drooping, and are more or less flattened from above downwards.

 

History^[7]

This tree was discovered by Née, who accompanied Malaspina in his voyage round the world during the years 1789 to 1794; and his specimen, gathered at Nootka Sound, is preserved in the Natural History Museum at South Kensington. It was referred to by James Donn, in Hortus Cantab. ed. 4 (1807), as Thuya plicata, without any description; and subsequently D. Don drew up from it the oldest description of the species under the same name. The Thuya plicata of gardens, which was early in cultivation, is a variety of Thuya occidentalis, and has no connection with the plant of Née.

Archibald Menzies, who accompanied Vancouver's expedition as botanist, gathered specimens also at Nootka Sound in 1795. Nuttall received specimens later from the Flathead river, on which he founded his description of the species as Thuya gigantea. It was introduced into cultivation^[8] in 1853 by W. Lobb, and distributed from Veitch's nursery at Exeter as Thuya Lobbi, as at that time Nuttall's name Thuya gigantea was wrongly applied to Libocedrus decurrens, and Don's name. Thuya plicata, in a similar erroneous way, had gone into common use for a variety of Thuya occidentalis. Afterwards the tree became generally known in England as Thuya gigantea; and it is unfortunate that Don's name, Thuya plicata, must, following the law of priority, be substituted for a name so well known and so established as gigantea. This change of name has, however, been adopted in the Kew Hand List of Conifers, and by Sudworth and Sargent in North America, and on the whole it is now most convenient to adopt the name Thuya plicata. (A.H.)

 

Distribution

This tree is, next to the Douglas fir, the most important from an economic point of view in northern Oregon, Washington, and British Columbia.

It extends in the north as far as southern Alaska, in the east to the Coeur d'Alène Mountains in Idaho and to north-western Montana, and in the south to Mendocino County in northern California. It is known as Cedar, or Red Cedar, and is found most abundantly on wet soils and in wet climates, ascending from sea level to an elevation, according to Sargent, of 6000 feet, where it becomes a low shrub. It is scarce in the dry belt of country east of the Cascade Mountains, but common in the Selkirk and Gold ranges, though, so far as I know, it never extends to the eastern side of the Rocky Mountains.

On the coast and in Vancouver Island it attains an immense size. I have never measured trees more than 200 to 220 feet high, but Prof Sheldon says that it attains 250 feet in Oregon, though no actual measurements are given.^[9] As regards their girth, I have measured two trees which may have grown from the same root, so close do they stand together, one of which was 39, the other 25 feet at 5 feet from the ground. These stand on Mr. Barkley's farm in Vancouver Island, in swampy land near sea level, and are figured in Plate 56.^[10] At over 2000 feet elevation in Oregon I measured another, also a twin tree, which was 30 feet in girth. Mr. Anderson states that he has seen Indian canoes 6 feet and more from the level of the gunwale to the bottom, hewn out of a log of this tree, such canoes being often 50 feet and more long, A hewn plank 5 feet wide by 15 feet long is in the museum at Victoria, B.C., and split boards, quite straight, 12 feet long and 15 inches wide, are made from it without difficulty.

The natural reproduction by seed was, wherever I saw it, very good, though in the densest shade the western hemlock seemed to have the advantage.

 

Cultivation

Wherever I have seen this tree growing in England and Scotland it is a vigorous, healthy tree of great beauty and promise, and one that I think is likely in fifty years or so to become a more valuable timber tree than the silver fir or spruce.

It has been stated in a report by Herr Bohm, in the March number of the Zeitschrift für Forst. u. Jagdweser for 1896,^[11] that the parasitic fungus Pestalozzia funerea has done serious damage to the tree in North Germany, and statements to the same effect have been made elsewhere; but I can say that out of the thousands of this tree that I have raised from English seed and planted out in a bad soil and climate, I have never had any die from any disease whatever, and have found it an easier tree both to raise and to transplant than any other conifer. It will grow on almost any soil at the rate of at least one foot per annum, as in damp, cold bottoms where the spruce will hardly thrive, on the poor dry oolite soil of the Cotswold hills, and seems equally indifferent to wind, damp, and spring frosts.^[12] It seldom loses its leader, is rarely blown down, endures heavy shade, and transplants both in early autumn and late spring with great readiness. It has, therefore, every good quality a forest tree can have, except the as yet unproved one of cleaning its trunk from branches without pruning.

And as this has not yet been properly tested by thick planting, I venture to say that there is no conifer better worthy of an extensive trial as a timber tree for such purposes as the larch is now used, and especially for fencing posts, for which its remarkable durability in the ground seems to make it most valuable.^[13]

I should therefore recommend that this tree should be planted at distances of 6 to 8 feet apart in situations where larch will not thrive, and not thinned as long as the trees keep healthy.

In the New England states it is not hardy enough to live in many places, but Professor Sargent tells me that a variety raised from seed from the Coeur d'Alène mountains in northern Idaho is hardy at Boston, where the form from the Pacific coast is tender, just as in the case of the Douglas fir.

No reliable tests, so far as I know, have yet been made in England or America as to the breaking strain and strength of this wood, but Sheldon states that it is used for telegraph posts in Oregon, and though its branches die off so slowly that the home-grown timber may probably be knotty, it is certainly not worse in this respect than spruce, to which I should consider it in every respect a superior forest tree.

The seed usually ripens about the end of October, and is very freely produced in most seasons. It soon sheds when ripe, and should be sown in boxes or in the open ground in early spring. I have tried both plans with great success, and find it best to plant the seedlings at two years old in nursery lines, and plant out the trees finally either in the early autumn or spring, when the deaths will be very small if the roots are not allowed to dry before planting.

There is very little variation among the seedlings, which grow rapidly in moist soil, and are less liable to suffer from spring frost than most trees, though if planted in mid-winter the tops are liable to die back.

There is no reason why this tree should not be sold in nurseries at the price of spruce except the absence of a regular demand, as it can be got up to a proper size for planting in two years less time.

The tree seeds itself very rapidly on sandy soil in many parts of the west and south of England, though liable to be thrown out of the ground by frost during the first year, and often destroyed by rabbits. On the lower greensand at Blackmoor, Hants, self-sown seedlings were quite numerous, both of this tree and of many other conifers, but rabbits are not allowed here, and both Lord and Lady Selborne take great interest in self-sown seedlings.

 

Remarkable Trees

The giant Thuya has not been long enough in cultivation to show whether it will attain the same dimensions that it does in America, but there are many trees which are already 60 to 70 feet in height at less than fifty years from seed.

By far the finest that I have seen or heard of are at Fonthill Abbey, Wilts, the residence of Lady Octavia Shaw-Stewart, which were raised in the late Duke of Westminster's gardens at Eaton Hall from seeds collected for Lord Stalbridge in 1860. Here, on a bed of greensand at an elevation of 400 to 500 feet, well sheltered from wind, are growing some of the finest and best grown conifers in Great Britain. In a group of three Thuyas, the middle one measured in 1906, as nearly as I could ascertain, not less than 90 and probably 95 feet in height by 10 feet in girth, and already began to show the buttressed trunk which is so characteristic in its native country. The other two trees were not much less in size, and all were a picture of health and symmetry (Plate 57).

The next tallest that we know of is a tree at Albury Park, the Surrey seat of the Duke of Northumberland. This was measured by Henry in 1904, and by myself in 1905, but owing to the way in which it is shut in by other trees it is difficult to measure accurately, and though the late Mr. Leach, the head gardener at Albury, and Dr. Henry both considered it about 90 feet high, I should not like to say that it is over 80, with a girth of 7 feet 6 inches. It is, however, a very healthy and vigorous tree, and growing fast, and the Duke's agent and gardener both hold a very high opinion of the probable value of the tree for timber, and are planting it largely on the estate. See Gard. Chron. Jan. 30, 1892, where an account is given of the trees at Albury in which Mr. Leach is quoted as saying: "If I had 1000 acres to plant with trees that would give the most remunerative return in a given time, the above would be my mainstay."

Sir Charles Strickland, one of the oldest and most experienced planters in England, also has a high opinion of this tree, and is quoted as follows by Mr. A.D. Webster in an article on this tree in Trans. Scottish Arb. Soc. vol. xii. p. 343:—"There is a hillside here (Hildenley, Yorkshire), with a thin soil upon limestone rock, which I planted two or three times over with very small success—chiefly, I believe, on account of the extreme dryness of the site. The Thuya grows there with great vigour, and I have scarcely lost one of those planted. Among the other merits of this Thuya is the ease with which it may be transplanted, owing to its having bushy, fibrous roots, instead of the long tangles which larch and many other conifers have."

I saw this plantation in 1905, and though the situation is too dry for Thuya to grow to any size, it bears out Sir Charles's good opinion. He has continued to raise the tree largely from his own seed, and is planting them largely at 5 feet apart, without mixture.

At Castlehill, North Devon, the seat of Earl Fortescue, there are also very fine specimens of Thuya plicata. The best is growing in a quarry in a well-sheltered place, but on dry, rocky ground. It measured in April 1905 about 74 feet high by 5 feet 11 inches in girth, and bids fair to become a noble tree.

At Fulmodestone, Norfolk, there are two trees, planted in 1863, which measured in 1905, 67 feet by 7 feet, and 61 feet by 6 feet 8 inches, and have natural seedlings around them.

At Coolhurst, near Horsham, Mr. C. Scrace Dickens showed me a very fine and symmetrical tree 75½ feet high by 5½ in girth, and only 8 yards in the spread of its branches.

At many places in the south-west of England trees of from 65 to 70 feet are growing of which the following are the best we have measured ourselves:—Linton Park, Kent, 70 feet by 7 feet 1 inch in 1902; Dropmore, Bucks, 68 feet by 6 feet 10 inches in 1905; Killerton, Devonshire, 68 feet by 7 feet 10 inches in 1905; Bicton, Devonshire, 70 feet by 8 feet 2 inches in 1902; Blackmoor, Hants, 60 feet by 6 feet.

In Wales a tree at Hafodunos measured 65 feet 6 inches by 9 feet 7 inches in 1904, with natural seedlings a few feet from its base on the stump of an old tree; at Welfield, near Builth, the seat of E.D. Thomas, Esq., a tree 68 feet high and 6J feet in girth was flourishing on the Llandilo slate formation; and at Penrhyn Castle Mr. Richards showed me a well-shaped and healthy young tree about 50 feet high, one of fifty which had been transplanted when about 18 feet high, only one of which died after being moved.

In Scotland Thuya plicata flourishes in the south and west, as well as in England. At Inverary Castle a tree only 25 feet high in 1892 is now over 60. At Poltalloch there are many, of which one in 1905 was 65 feet by 7 feet 2 inches. As far north as Gordon Castle it grows well, and at most of the places from which reports were sent to the Conifer conference in 1892 it is spoken of as healthy and vigorous. At Murthly, Scone, and Castle Menzies, I have seen fine trees, but have not measured any of remarkable size.

At Monreith, Dumfriesshire, the seat of Sir Herbert Maxwell, Bart., who has a high opinion of this tree, a large number have been raised from seed and planted out, but are as yet too young to measure.

At Benmore, near Dunoon in Argyllshire, the property of H.J. Younger, Esq., where there are very interesting plantations of several kinds of exotic conifers made in the winter of 1878–79, Thuya, when mixed with the common larch and Douglas fir on a steep hillside at 250 to 500 feet above sea-level, is now being suppressed by these species, which grow more vigorously. However, in one part of the plantation, near Ardbeg, at only 50 feet above sea-level and in fairly good soil, the Thuya was holding its own fairly well with the Douglas, and had attained, at twenty-four years old, 50 feet in height with clean stems varying from 25 to 38 inches in girth at 5 feet from the ground. Near Kilmun, on the same property, there is now, according to the forester, about 1½ acres of Thuya, which has been planted mixed with larch. The larch has been cut out, and the whole area is now pure Thuya, with clean stems larger in size than in the other parts of the plantations where it occurs mixed with Douglas fir.^[14]

In Ireland the best trees we know of are at Castlewellan, co. Down, 65 feet in 1903; Hamwood, co. Meath, 71 feet by 6 feet 3 inches in 1904; Churchill, co. Armagh, 68 feet by 5 feet 10 inches in 1904; Adare, co. Limerick, 71 feet by 7 feet 7 inches in 1903.

At Dartrey, in co. Monaghan, the Earl of Dartrey planted in 1882 a considerable area of slightly hilly ground with a mixture of larch, spruce, Douglas fir, and Thuya. In 1904, twenty-two years after planting, of the four species, all grown densely under the same conditions, the Thuya had made the most timber, the trees averaging 40 to 50 feet in height by 4½ feet in girth. The Douglas fir was slightly taller, but not so stout in the stem, averaging about 3½ feet in girth. The Earl of Dartrey speaks very highly of the timber of Thuya, which he considers to be superior to that of the best larch.

At Brockley Park, Queen's Co., the residence of Mr. Wm. Young, there are trees growing on light soil on limestone, which have made 40 cubic feet of timber in 30 years, and 50 feet in 35 years. The tallest tree, 30 years old, was in 1906 64 feet high by 7 feet 9 inches at a foot from the ground, and 3½ feet girth at 24 feet up; and its branches were 105 feet in circumference.

 

Timber

Sargent says, Garden and Forest, iv. p. 109: "The wood is very valuable; it is light, soft, and easily worked, and so durable in contact with the ground, or when exposed to the elements, that no one has ever known it long enough to see it decay."

The great value of the cedar for shingle-making has long been known, and several instances were mentioned by reliable people in Vancouver Island of handmade shingles, or "shakes" as they are called, remaining good 40 to 50 years on roofs without decaying in the wet climate of this island.

They are now manufactured on a very large scale by machinery in all the Puget Sound mills, and exported largely to the middle and eastern states in neat bundles, and I have no doubt that, if carefully selected and laid, such shingles would be very suitable for roofing in England. Sargent says, Garden and Forest, iv. p. 242, "that nearly 100 mills were in 1891 exclusively devoted to making Red Cedar shingles, and that the combined output of half of these operated by one company was 3,50x5,000 per diem. They are now supplanting the Pine shingle of Michigan, the Cypress shingle of the south, and the Redwood shingle of California."

As a rule in the American forests, they begin to decay at the heart long before they attain their full growth, and the trunk seems to continue growing round the hollow centre for an almost indefinite time, as in the case of the yew. On drier land it keeps sound longer, and if cut when 2 to 3 feet in diameter the wood is probably at its best. It resists decay for an immense time when fallen.

For inside finish the wood is excellent, though not hard enough for flooring and wainscot, or strong enough for joists. For ceiling and panelling it is most ornamental when well cut, as I saw in the Hotel at Duncan's, Vancouver Island.

Mr. Stewart has found at Benmore that it is very suitable for all estate purposes, and prefers it to larch for planking and fencing, as he finds it less liable to warp and crack.(H.J.E.)

 

 

THUYA OCCIDENTALIS, Western Arbor Vitæ

 

Thuya occidentalis, Linnæus, Sp. Pl. 1002 (1753); Loudon, Arb. et Frut. Brit. iv. 2454 (1838); Sargent, Silva N. America, x. 126, t. 532 (1896), and Manual Trees N. America, 74, (1905); Masters, Gard. Chron. xxi. 213, figs. 67, 68, and 258, fig. 86 (1897); Kent, in Veitch's Man. Conif. 244 (1900).

Thuya plicata, Hort. (non Don).

 

A tree, attaining a height of 50 to 60 feet, with a stout and buttressed trunk, sometimes 6 feet in diameter. It often divides near the base into two or three stems. In England the branches, short and spreading, form a tree pyramidal in outline, which is not so dense in foliage as Thuya plicata. Bark of the trunk scaling off in thin papery rolls, but not so freely or so finely as in Thuya japonica. The branches when of no great size begin to show scaly bark.

The branch systems are disposed in horizontal planes, resembling those of Thuya plicata; but their main axes are flattened, being compressed from below upwards, while the leaves are shorter than in that species, ending in similar long points. The flat leaves on the main axes are studded with conspicuous large circular elevated glands. The smaller leaves on the ultimate branchlets vary as regards the presence or absence of glands; the lateral pairs are shorter than and not so acutely pointed as in Thuya plicata. The foliage is dark green above, pale green and not marked with white streaks below.

The male flowers, minute and globose, are composed of three decussate pairs of stamens. The female flowers are yellow.

The cones become deflected when ripe, as in Thuya plicata. They are oblong, light brown, and composed of 4 to 5 pairs of scales, of which the 2nd and 3rd pairs are larger than the others, and fertile. The scales are ovate or spathulate, ending in a rounded or acute apex, with a minute external process, which is generally much less developed than is the case in Thuya plicata. The seeds, usually two on each fertile scale, are scarcely distinguishable from those of the last-named species.

Seedling.^[15]—Cotyledons as in Thuya plicata. The caulicle and stem are quadrangular. The first two true leaves are opposite, spreading, and similar to the cotyledons, though smaller. These are followed by 5 or more whorls or pseudowhorls, each of three similar leaves, linear, acute, and sessile. The ultimate leaves are opposite, decussate, and adnate for the greater part of their length to branchlets, which are flattened from above downwards.

 

Varieties

Few trees, except Cupressus Lawsoniana, show a greater tendency to variation in the seed-bed. Sargent says that if anyone will sow a quantity of seed he will be sure to find forms among the seedlings as novel and as interesting as any now in cultivation. Many of the varieties only show their distinctive characteristics when young, and soon grow up into the normal form. Beissner gives as many as forty varieties; but it is doubtful if all these are recognisable. Those commonly met with in cultivation in this country are enumerated below:—

1. Var. ericoides.^[16]

Retinospora dubia, Carrière, Conif. ed. 2, p. 141.

A form in which the seedling foliage is fixed and preserved. It is a dwarf, compact, rounded, or somewhat pyramidal shrub, with slender branchlets, on which the leaves, heath-like in appearance, are borne in distant decussate pairs. They are spreading, linear, and soft in texture, becoming brown in winter. This shrub resembles Cupressus pisifera, var. squarrosa; but in the latter the leaves are much whiter on both surfaces, and do not brown in winter. The latter also attains a much larger size, and often becomes a large shrub or small tree,

2. Var. Ellwangeriana.

Retinospora Ellwangeriana, Carrière, Rev. Hort. 1869, p. 349.

This is a transition form, in which both kinds of foliage, seedling and adult, appear on the shrub, which may attain a considerable size. There is no regularity in the distribution of the two kinds of leaves; but in shrubs at Kew of this variety the juvenile foliage persists on branchlets in the interior shaded parts, the external branchlets having adult foliage.

It was probably this form which M'Nab^[17] mentions as having seen in 1866 in quantity in the nursery of Messrs. P. Lawson and Sons, who had received it from Messrs. Ellwanger and Barry of America under the name of Tom -Thumb Arbor Vitæ. M'Nab states that the heath-like leaves have a slight smell of juniper, while the other foliage has the odour of ordinary Thuya occidentalis.

3. Var. plicata, Masters, Gard. Chron. xxi. 258, fig. 86 (1897).

Thuya plicata, Parlatore, D.C. Prod. xvi. 457.

A tree differing from the type in the branch-systems tending to assume the vertical plane, being curved so that the ultimate branchlets lie in different planes. The foliage is conspicuously glandular, the lateral leaves being flattened, so that they become almost like the median ones in appearance. According to Kent the foliage shows a brownish tint.

This variety was long considered to be a distinct species; but it is only a seedling of Thuya occidentalis, with which it agrees in cones and in general character of the leaves.

4. Var. Wareana. This only differs from the last in the colour of the foliage, which is a deep green without any brown tinge. It was raised by Mr. Ware of Coventry.^[18] According to Masters^[19] it has larger leaves than var. plicata, and corresponds very closely with native specimens of Thuya occidentalis gathered at Niagara.

5. Var. dumosa. A dwarf shrub, with the foliage and branchlets of var. plicata.

6. Var. pendula. A shrub with pendulous branches and branchlets.

7. Var. erecta. Branches slender and erect. In var. erecta viridis the foliage is dark green and shining on the upper surface. It originated in Messrs, Paul's nurseries at Cheshunt.^[20]

8. Var. Späthi. A monstrous form, with seedling foliage on the younger branchlets, older branchlets being tetragonal, and clothed with sharp-pointed adult leaves.

9. Various forms occur with coloured foliage, as lutea, aurea, vervæneana, etc.

Thuya occidentalis was probably the first American tree cultivated in Europe. Belon^[21] describes it as occurring in a garden at Paris about the middle of the sixteenth century. It was introduced into England prior to 1597, as it is mentioned by Gerard in his Herball published in that year.(A.H.)

 

Distribution, etc.

According to Sargent, Thuya occidentalis frequently forms nearly impenetrable forests on swampy ground, or occupies the rocky banks of streams from Nova Scotia and New Brunswick, north-westward to Cedar Lake at the mouth of the Saskatchewan, and southward through the northern * states to southern New Hampshire, central Massachusetts and New York, northern Pennsylvania, central Michigan, northern Illinois, and central Minnesota, and along the high Alleghany mountains to southern Virginia and north-eastern Tennessee; very common in the north, less abundant and of smaller size southward; on the southern Alleghany mountains only at high elevations.

Mr. James M. Macoun says of this tree in his excellent pamphlet. The Forest Wealth of Canada (Ottawa, 1904), that the white cedar, as it is there usually called—though in New England this name is always given to Cupressus thyoides—is very rare in Nova Scotia, but abundant throughout New Brunswick and Ontario. It grows to a considerable height, but seldom exceeds 2 feet in diameter. The wood is soft and not strong, and has never been much used for timber, but is unexcelled for shingles. It is chiefly used for fence rails and posts, railway ties, and telegraph posts. No other wood is used in any quantity for telegraph poles in Ontario and Quebec. It is very durable in contact with the soil or when exposed to the weather.

I saw the tree abundantly in wet swamps and also on dry ground near Ottawa, where, in Rockcliff Park, good though not large trees of it may be seen, the best having all been cut out for telegraph poles. On dry, rocky ground the tree grows freely from the stool, and in wet places in the woods reproduces abundantly from seed, which was ripe at the end of September, and, as usual in the forests of Canada, germinates and grows best when it falls on a rotten log.

 

 

Remarkable Trees

Thuya occidentalis never attains to a considerable size when planted in this country. There is a specimen at White Knights, near Reading, of great age, which is now dying at the top. According to the gardener there it has not made any growth for the last thirty-five years. It measured in 1904, 41 feet in height by 4 feet in girth. At Stratton Strawless, Norfolk, there is also a specimen of considerable age, remarkable for the pendulous habit of the branches, which is 35 feet in height. There are more large specimens at Belton Park than at any other place I know in England, the largest I have measured being 41 feet by 3 feet 9 inches. Henry, however, in 1904 measured one at Arley Castle as tall, which divides into three stems near the ground, where it measures 7 feet 6 inches in girth. At Auchendrane, Ayrshire, Renwick measured a tree in 1902—which, according to a specimen procured by him in 1906, was Thuya occidentalis—as 42 feet high by 6 feet 8 inches in girth, with a bole of 12 feet.

It seems to be one of the best conifers for making shelter hedges in gardens, as it stands clipping well, and for this purpose may be relied on to attain 1 5 to 20 feet in height in any fair soil. As it grows slowly at first when raised from seed, it is usually propagated by cuttings.(H.J.E.)

 

 

THUYA JAPONICA, Japanese Thuya

 

Thuya japonica, Maximowicz, Mél. Biol. i. 26 (1866); Masters, Jour. Linn. Soc. (Bot.) xviii. 486 (1881), and Gard. Chron. xxi. 258, fig. 87 (1897); Revue Horticole, 1896, p. 160; Kent, in Veitch's Man. Coniferæ, 244 (1900); Shirasawa, Icon. des Essences forestières du Japon, 28, t. xi. 18–34 (1900).

Thuya Standishii, Carrière, Traité Gén. Conif. 108 (1867).

Thuya gigantea, var. japonica, Franchet et Savatier, Enum. Pl. Jap. i. 469 (1875).

Thujopsis Standishii, Gordon, Pin. Suppl. 100 (1862).

 

A tree attaining, according to Shirasawa, a height of 90 feet in Japan, with a tapering stem, open in habit as cultivated in England, and not forming such a dense pyramid as Thuya plicata. Bark of the trunk scaling off in very narrow longitudinal papery strips. The bark commences to scale on young branches of less than a half inch in diameter. The branches curve upwards towards their extremities.

The branch-systems, 3–4 pinnate, are disposed in horizontal planes, which droop at their outer extremities. Primary axes terete, with leaves densely crowded, all the four sets ending in short, rigid, thick, free points, glands being absent. The leaves on the ultimate branchlets are obtuse, and not acutely pointed as in Thuya plicata; and glands may be present or absent on the flat leaves. The foliage is light green above, while on the under surface there are whitish streaks, somewhat triangular in outline, which exceed in area the greener parts.

Male flowers cylindrical, with 6 decussate pairs of stamens. The cones are deflected, ovoid, and composed of 5 to 6 pairs of scales, of which the second and third pairs are larger than the others and fertile. The scales are broadly oval, with a rounded apex, from below which externally is given off a short, broad, triangular process, projecting from the scale at right angles or nearly so. The seeds, three to each fertile scale, and nearly equal to it in length, differ considerably from those of Thuya plicata and Thuya occidentalis, the wing being narrow, not so scarious in texture, entire, and not notched at the summit.

Fortune discovered Thuya japonica in cultivation around Tokyo in 1860, and sent home seeds of it to the nursery of Mr. Standish at Ascot, who distributed plants under the name of Thujopsis Standishii. Maximowicz, who had also seen it cultivated at Tokyo, gave the species its first authoritative name in 1861. Maries found it growing wild on the mountains of Nikko, in central Japan, in 1877. Sargent,^[22] who, in company with James H. Veitch, met with a few solitary specimens on the shores of Lake Yumoto in these mountains, at 4000 feet altitude, describes it as a small pyramidal tree of 20 to 30 feet high, of open and graceful habit, with pale green foliage and bright red bark. Shirasawa, however, states that it attains a height of 90 feet, with a diameter of stem of nearly 6 feet; and that it grows in the central chain of Hondo, in the mountains of Kaga, Hida, and Shinano, at elevations of 2000 to 6600 feet. The stem, according to Shirasawa, is often twisted, and gives off great wide-spreading branches.(A.H.)

 

According to Komaror, Floræ Manshuriæ, i. 206 (1901), Thuya japonica grows wild abundantly in northern Corea in the Samsu district, but was not observed by him in Manchuria or elsewhere on the mainland.

This tree is not, so far as I saw, as common in Japan, where it is called Nezuko, as Cupressus obtusa or C. pisifera, though it is said by Goto^[23] to be found in the provinces of Yamato, Bungo, Satsuma, Omi, Iwashiro, Shimotsuke, and Uzen, at an elevation of from about 3000 to 6000 feet.

The only place where I saw it wild was at Yumoto, above Nikko, where it was scattered in mixed forest with Tsuga, Thujopsis, birches, and other deciduous trees, and it is said to be never found in unmixed woods. At Koyasan I found small trees of it, perhaps planted, and brought away a seedling, which is now living at Colesborne.

At Atera, in the Kisogawa district, the forester told me that it grows best as a young tree in shade, and that where Cupressus obtusa has been felled it often comes up from seed. It does not attain very large dimensions, so far as I could learn, and is not considered a tree of much economic importance.

The timber is light and used for carpentry. It sometimes has a very pretty figure, and in old trees is of a pale grey colour, though perhaps this is only assumed by trees which were dead before cutting. It is cut into thin boards, and used for ceilings and other inside work, and is said to cost about 2d. per square foot in the board at Tokyo, and to make very durable shingles.

In Great Britain the tree seems to grow slowly, and is not common in gardens. The largest I have seen is a grafted and very spreading tree in Mr. W.H. Griffiths' garden at Campden, Gloucestershire, which is about 25 feet by 2 feet, and probably one of the oldest in England. It has produced fertile seeds from which plants have been raised. The largest recorded at the Conifer Conference was at Dalkeith Palace, where it was 15 feet high in 1891. A tree at Kilmacurragh, co. Wicklow, Ireland, was 24 feet by 2 feet 4 inches in 1906, and bears fruit. Another at Castlewellan measured 25 feet high in the same year.(H.J.E.)

 

THUYA ORIENTALIS, Chinese Arbor Vitæ

 

Thuya orientalis, Linnæus, Sp. Pl. 1002 (1753); Loudon, Arb. et Frut. Brit. iv. 2459 (1838); Masters, Jour. Linn. Soc. (Bot.) xviii. 488; Kent, in Veitch's Man. Coniferæ, 248 (1900).

Biota orientalis, Endlicher, Syn. Conif. 47 (1847).

 

A tree or dense shrub, with the trunk often branching into several stems from near the base. Bark of trunk thin, reddish brown, and separating in longitudinal papery scales. The bark begins to scale on branches which are about a half inch in thickness. The branches are ascending, becoming tortuose at their extremities, and giving off more or less equal -sided branch -systems, which are disposed in vertical planes, with their inner edge directed towards the stem of the tree. These are finer and more closely ramified than in the preceding species. Their main axes are terete; bearing median leaves, marked by a glandular longitudinal depression, and ending in triangular free points (not appressed to the axis); and lateral leaves, ending in similar but longer free points, which are thickened at the part where they become free and reflected away from the axis. The leaves on the ultimate branchlets are closely imbricated, appressed to the stem, and marked with longitudinal depressions.

The male flowers are globose and composed of 4 decussate pairs of stamens.

The cones^[24] are erect and ovoid, fleshy and bluish before ripening, but ultimately becoming dry and woody, the scales gaping widely. Scales, usually 3 pairs (occasionally a fourth pair, sterile and much reduced, appears at the base), the two lowest fertile, the uppermost pair aborted and sterile: ovate, obtuse, thick, and ligneous, bearing externally below the apex a hooked process. The seeds, 2 on each scale, are large, ovoid, without wings, brown in colour, with a white, large, oblong hilum.

The seedling^[25] resembles that of the other species of Thuya, except that the cotyledons are much larger, about an inch in length.

 

Varieties

A great number of varieties of this species have been obtained. The most remarkable of these are:—

I. Var. pendula, Masters, Jour. R. Hort. Soc. xiv. 252.

Thuya pendula, Lambert, Genus Pinus, ed. 2, ii. 115 t. 52; Siebold et Zuccarini, Fl. Jap. ii. 30 t. 117.

Thuya filiformis, Lindley, Bot. Reg. xxviii. t. 20 (1842).

Biota pendula, Endlicher, Syn. Conif. 49.

Cupressus pendula, Thunberg, Fl. Jap. 265.

 

A shrub, with a straight trunk, bare of branches below. The branchlets, numerous, long, flexile, cord - like, unbranched or only slightly branched, are produced in irregular fascicles of 5 to 20 or more at irregular intervals along the branches. They are slender and pendent, and bear leaves distantly placed in 4 rows in decussate pairs. The leaves, broadly decurrent at the base and long acuminate at the apex, spread out from the branchlets at an acute angle. Cones are occasionally borne, which are like those of the type.^[26] There is a specimen at Kew of a plant raised from seed of this variety, which is ordinary Thuya orientalis. It was sent from the Botanic Garden at Turin by Mr. Hanbury in 1860.

There are several forms of this variety, differing in habit and length of leaves; in one the branchlets are tetragonal.

This shrub was first observed by Thunberg in Japan, and specimens were collected near Yokohama by Maximowicz. It was also met with by Fortune in China, and has been raised in Europe.

2. Var. decussata.

Retinospora Juniperoides, Carrière, Conif. ed. 2, p. 140.

A low shrub, with erect stems and branches, bearing foliage like that of the seedling. The leaves are in 4 rows in decussate pairs, spreading, and resembling those of a juniper, except that the points are not prickly. They are greyish green in summer, changing to brown in winter.

3. Var. Meldensis.

Biota Meldensis, Lawson, in Gordon, Pinetum, 37.

A small tree with ascending flexible branches. It is a transition form, bearing acute acicular spreading leaves like that of the seedling, and occasionally leaves of the adult character. The leaves are bluish green, changing to brown in the winter. This plant was raised from seeds of Thuya orientalis gathered in the cemetery of Trilbardoux near Meaux in France; and for a long time was supposed to be a cross between Thuya orientalis and Juniperus virginiana.

4. Var. intermedia.

Biota orientalis intermedia, Carrière, Man. des Pl. iv. 322.

This is also a transition form. It is a shrub with elongated pendent branchlets, the ramifications of which arise from all sides of the axis, not remaining in one plane. There are two kinds of leaves, those towards the ends of the branchlets resembling the adult foliage of Thuya orientalis, while those on older parts are spreading, arranged in decussate pairs, oval-lanceolate, decurrent at the base, and acute at the apex. In Var. funiculata, if it is in reality distinguishable, there appears to be a larger proportion of adult foliage.

Many other varieties have been described: some of peculiar habit, as gracilis and pyramidalis, which are fastigiate; others with coloured or variegated foliage, as aurea, argenteo-variegata, aureo-variegata. Var. ericoides of this species closely resembles the variety of the same name belonging to Thuya occidentalis; the latter is slightly whiter on both surfaces of the leaves.

 

Distribution, etc.

Thuya orientalis occurs wild in the mountains of north China. It is common in the hills west of Pekin, where Fortune^[27] observed trees of a large size, 50 or 60 feet in height. Elsewhere in China it is only met with planted in cemeteries and temple grounds. It has been known to the Chinese from the earliest times as the Poh or Peh tree, and is mentioned in their classical books; it was planted around the graves of feudal princes, and its wood was used for making the coffins of great officials. The tree was introduced into Japan from China at an early period, probably like so many other Chinese plants, by the Buddhist missionaries. Japanese botanists are all agreed that it is not indigenous in Japan. Various other regions have been mentioned as being the home of Thuya orientalis, as Siberia, Turkestan, Himalayas, etc.; but specimens collected in these countries are undoubtedly from cultivated trees. The tree is mentioned by Gmelin in his Flora Siberica, i. 182 (1747); but only as occurring between Kiachta and Peking. Ledebour^[28] denies its existence in any part of Siberia.

Thuya orientalis was first grown in Europe at Leyden, some time before 1737, when Linnæus^[29] described the plant as Thuya strobilis uncinatis squamis reflexa acuminatis. Royen, who sent a specimen to Linnæus, mentions the species with considerable details in his account^[30] of the plants that were cultivated at that time in the Botanic Garden at Leyden; but his promised account of the history of its introduction apparently never was published. It is possible that it was raised from seed sent home by the Dutch from Japan, as Kaempfer, who travelled in that country from 1690 to 1692, collected specimens of Thuya orientalis which are still preserved in the Natural History Museum at South Kensington.^[31] Seeds were also soon afterwards sent to Paris by the missionaries in north China.^[32] The earliest account of it in England occurs in a letter dated February 1, 1743, from the Duke of Richmond to Collinson, as follows:— "I am sorry to find by Miller that I am not likely to have the Chinese Thuya. I own, if it belonged to anybody that would sell it, I should be foolish enough to offer ten guineas for it, because it is the only one in England that can match that which I have already." It was cultivated early by Miller^[33] in the Physic Garden at Chelsea.

Thuya orientalis never attains in this country any considerable dimensions. It ripens good seed; and at Kew, on a wall near the Director's office, may be seen a young tree which originated from a seed probably carried there by a bird from a tree in the gardens.

In the garden at Hampton Court, Herefordshire, there are a pair of fine specimens about 40 feet high, and about 7 feet round at the base, where they divide into several stems which have been formed into an arch over the path, and in most old gardens trees of 25 to 35 feet may be found, but, like T. japonica and T. occidentalis, it must be looked on as an ornamental shrub rather than a timber tree. (A.H.)

 

1. Thuya has been written Thuja in Linnæus, Hort. Cliff. 449 (1737), and Sp. Pl. 1002 (1753); and Thuia in Scopoli, Introd. 353 (1777).
2. The branchlets become brown in colour before they fall. See Masters, Gard. Chron. 1883, xx. 596.
3. In addition to the varieties, in which the foliage retains permanently the seedling character, other forms occur in cultivation, in which the leaves are intermediate in shape between those of the seedling and of the adult plant. These varieties resemble the so-called Retinospora forms of the genus Cupressus, and were formerly considered, like them, to belong to a distinct genus.
4. This species exhales a peculiar aromatic odour, which is different from that of the other Thuyas.
5. Jour. de Bot. 1899, p. 262. See also Masters in Jour. Linn. Soc. (Bot.) xxvi. 540.
6. Figured in Lubbock, Seedlings, ii. 551, fig. 676 (1892), and Sargent, loc. cit. t. 533, fig. 12.
7. See Masters, in Gard. Chron. loc. cit.
8. At the Royal Botanic Gardens, Edinburgh, there were in 1884 five trees of supposed Thuya gigantea, which were raised, it was said, from seed sent to Edinburgh by Jeffrey in 1851, while collecting for the Oregon Association. Three of these trees, according to Nicholson, were true gigantea, the other two being what is now known as Thuya occidentalis, var. plicata. See Woods and Forests, Feb. 27, and Mar. 19, 1884. These trees cannot now be identified.
9. In the Canadian Court of the Colonial Exhibition of 1886, there was shown a portion of a bole of this species, which was taken from a tree girthing 21 feet, and having a length of 250 feet. It came from British Columbia.—Gard. Chron. 1886, xxvi. 207.
10. An illustration of a tree growing near Snoqualmie Falls on the Seattle and International Railway, Washington, was given in The Pacific Rural Press in 1897. This is said to have been 107 feet 7 inches round at the base, and was supposed to have been over 1000 years old, but we know of no good evidence that it ever attains so great an age as this.
11. Cf. A.C. Forbes, Gard. Chron. 1896, xix. 554.
12. The very severe frost on May 20–21, 1905, when 10°–15° of frost were registered in many places, which killed many young beech trees in low situations at Colesborne, and checked the young growth considerably, killed none except a few of the weakest Thuyas which were freshly transplanted; but the autumn frost of the following October, when the trees were still in growth, seems to have done more harm, though the young trees did not die till the following spring.
13. I have recently been shown by Mr. Molyneux a plantation of Thuya gigantea and larch called Mays hill, made by him in 1888 on poor, heavy wheat land overlying chalk at Swanmore Park, Hants, the seat of W.H. Myers, Esq., M.P. Here the Thuyas have completely outgrown the larch, and in many cases suppressed them, and are 15 to 20 feet high, and quite healthy; whereas where the larch were planted alone in the same place they are diseased and sickly.
14. We are indebted to Mr. Angus Cameron, factor for the property, and to Mr. J.M. Stewart, forester, for further particulars of these plantations, for which we cannot now find space.
15. See Lubbock, Seedlings, ii. 548, 560 (1892).
16. A plant of this variety growing into the mature form at Meehan's nursery, Germantown, U.S., showed that it was only a juvenile state of Thuya occidentalis.—Garden and Forest, 1893, p. 378.
17. Trans. Edin. Bot. Soc. ix. 61, fig. (1868).
18. Gordon, Pinetum, ed. 2, p. 409.
19. Gard. Chron. xxi. 258 (1897).
20. Gard. Chron. xiv. 213 (1880).
21. Belon, De Arboribus Coniferis, p. 13 (1553).
22. Garden and Forest, 1893, p. 442, and 1897, p. 441.
23. Forestry of Japan (1904).
24. The cones ripen in one year, but frequently in England retain their seed till the spring of the following year.
25. Tubeuf, Samen, Früchte, u. Keimlinge, 104, fig. 144 (1891).
26. At Barton, a shrub of this variety produced cones, which had very long hooked processes on the scales (Bunbury, Arboretum Notes, 153).
27. Yedo and Peking, 307, 382 (1863). Fortune supposed that the wild tree in north China was distinct from that cultivated near Shanghai; but there is no doubt that the trees, which attain a great size in the hills west of Peking, are ordinary Thuya orientalis.
28. Comment, in Gmelini Fl. Sibericam, 60 (1841).
29. Hort. Cliff. 449 (1737).
30. Flora Leydensis Prodromus, 87 (1740).
31. I have seen these specimens. See Salisbury, Coniferous Plants of Kaempfer, in Jour. Science and Arts, ii. 313 (1817). Kaempfer does not mention the plant in his Amœnitates Exoticæ.
32. See Miller, Gard. Dict. ed. 6 (1752), and ed. 8 (1768), sub "Thuya."
33. Cf. Aiton, Hort. Kew. iii. 371 (1789).