The Trees of Great Britain & Ireland/Volume 3/Ostrya

by Henry John Elwes and Augustine Henry

 

OSTRYA

 

Ostrya, Scopoli, Fl. Carniol. 414 (1760); Bentham et Hooker, Gen. Pl. iii. 406 (1880); Winkler, in Engler, Pflanzenreich, iv. 61, Betulaceæ, 24 (1904).

Carpinus, Linnæus, Gen. Pl. 292 (ex parte) (1737).

 

Small deciduous trees, belonging to the order Betulacez, agreeing with the genus Carpinus in the characters of the branchlets, buds, foliage, and staminate flowers. Pistillate flowers, in dense erect spikes, inserted in pairs on the base of ovate acute leafy scales, each flower enclosed in a sac-like involucre, formed by the union of a bract and two bracteoles, which is open at the apex at the time of flowering, afterwards becoming closed. Calyx dentate, adnate to the two-celled inferior ovary; style short, divided into two linear subulate stigmatic branches; ovules solitary in each cell. Fruits: disposed in stalked ovoid strobiles, composed of densely imbricated involucres, which are vesicular, closed, flattened, membranous, longitudinally nerved, reticulate, pubescent at the apex, and hirsute at the base with sharp, rigid, stinging hairs. Nutlet, sessile in the involucre, ovoid, compressed, longitudinally ribbed, crowned by the remains of the calyx; seed solitary, pendulous.

Four species of Ostrya have been distinguished:—Ostrya Knowltoni, Coville, a rare tree in Arizona, not yet introduced, and three species, occurring in North America, Eastern Asia, and Europe and Asia Minor, which are so closely allied that they have been considered by most botanists to be only geographical races of one species. These three species are all in cultivation, and as they can be distinguished (see Key to Carpinus and Ostrya, p. 526), will be treated by us separately.

 

OSTRYA CARPINIFOLIA, Hop Hornbeam

 

Ostrya carpinifolia, Scopoli, Fl. Carniol. ii. 244 (1772); Willkomm, Forstliche Flora, 368 (1887); Mathieu, Flore Forestiére, 403 (1897).

Ostrya vulgaris, Willdenow, Sp. Pl. iv. 469 (1805); Loudon, Arb. et Frut. Brit. iii, 2015 (1838).

Ostrya italica, Spach. Ann. Sc. Nat. sér. 2, xvi. 246 (1841).

Ostrya italica, sub-species carpinifolia, Winkler, Betulaceæ, 22 (1904).

Ostrya Ostrya, Sargent, Silva N. Amer. ix. 32 (1896).

Carpinus Ostrya, Linnæus, Sp. Pl. 998 (1753).

 

A tree attaining 60 feet in height and 10 feet in girth; stem cylindrical, bark greyish, finely fissured, and scaly. Young branchlets with dense appressed pubescence. Leaves (Plate 201, Fig. 11) about 3 inches long by 1³⁄₄ inch wide, ovate, shortly acuminate at the apex, unequal and rounded at the base; margin sharply bi-serrate and ciliate; covered above and below with appressed pubescence, spreading more or less over the whole surface, and not confined to the midrib and nerves, as in Carpinus Betulus, and with minute axil tufts on the lower surface; nerves twelve to fifteen pairs; petiole ¹⁄₄ to ³⁄₈ inch long, appressed pubescent; stipules persistent during summer. Nutlet ovoid, ¹⁄₆ inch long, crowned by a tuft of hairs; calyx-limb obsolete.

In winter the twigs are slender, zigzag, more or less pubescent. No true terminal bud is formed, the apex of the branchlet falling off in summer and leaving a minute circular scar at the side of the uppermost axillary bud. Buds small, ³⁄₁₆ inch long, ovoid, viscid, set obliquely on prominent leaf-cushions; scales 6 to 9, imbricated, greenish with a dark brown margin, more or less pubescent. Leaf-scar semicircular, with two bundle-dots above and one group of three smaller dots below.

Ostrya carpinifolia reaches its most westerly point in the extreme south-eastern corner of France, where it occupies a few isolated stations in the Basses-Alpes and Alpes-Maritimes Departments. In the forest of Miolans,^[1] in the Basses-Alpes, which is mainly composed of Pinus sylvestris, it is found on a northern slope, over an area of about 400 acres, occurring chiefly as undergrowth and ascending to about 2700 feet altitude. In the Alpes-Maritimes it descends in some places to nearly sealevel. It extends eastward through Southern Switzerland, the Tyrol (where,^[2] near Botzen, it ascends to 3500 feet altitude), Carinthia, and Lower Styria to Southern Hungary, and spreads southwards through Carniola, Croatia, and the Balkan States to Greece, growing usually in rocky situations, more commonly on limestone than on other formations. It is common throughout Italy and Sicily in the oak and chestnut regions, ascending to 3800 feet elevation; and forms woods of considerable extent around Lake Como, especially above Lecco, on the shores of Lake Lugano, and at Gaudria and Salvatore.^[2] It occurs as a rare tree in Corsica and Sardinia. It is also met with in Asia Minor and in the Lebanon. It attains about a hundred years of age; and according to Pardé^[3] produces coppice shoots like the hornbeam. (A.H.)

 

Cultivation

It was introduced into cultivation in England some time before 1724, as it is mentioned in Furber's Nursery Catalogue published in that year. Though an ornamental tree which attains a good size and is perfectly hardy, it has always been very rare in this country. According to Mouillefert^[4] its growth is about equal to that of the Hornbeam. I have raised plants from French seed which grow faster on my soil than those of the hornbeam, and seem at least as hardy, as they were uninjured by the severe spring frost of May 21–23, 1905, and ripened their young wood well in October. They,may be distinguished by the larger leaves with a pair of persistent linear stipules at the base.

 

Remarkable Trees

From the dimensions given by foreign authors I doubt whether in its native country the Hop Hornbeam ever attains a much larger size than the one which I figure (Plate 153). This remarkable tree is at Langley Park, near Norwich, the seat of Sir Reginald Beauchamp, and cannot be of great age, as it is not mentioned in an account of this place in Grigor's Eastern Arboretum, published in 1841. It is grafted on a stock of the hornbeam which measures 8 feet in girth below the graft, while the trunk above it is no less than 15 feet 8 inches. Its height is difficult to estimate, but may be about 50 feet.

A large tree formerly grew at Kew, on which Mr. J.G. Jack, in Garden and Forest, v. 602, remarks as follows:—"An unusually fine specimen of a hop hornbeam, 50 feet high, branching near the ground and spreading about 70 feet, with a trunk over 3 feet in diameter, was grafted on a stock of hornbeam at 23 feet from the ground, and is a good deal larger than its stock, with a swelling at the point of juncture. No one can help remarking the striking contrast between the rough bark of the Ostrya and the comparatively smooth bark of the Carpinus."

This tree was perhaps the one figured by Loudon^[5] in 1838, which was then said to be 60 feet high, with a trunk 3 feet in diameter, and the finest specimen in England at that time. In 1890 it was figured in the Gardeners' Chronicle^[6] as a handsome wide-spreading tree, but soon after began to decay, and was cut down in 1897,^[7] when it measured 59 feet high by 9 feet 4 inches in girth at 3 feet. Fruit was abundantly produced; but no perfect seeds were ever developed. A part of its trunk is preserved in the Museum at Kew, and I am indebted to the Director for a sample of the timber, which somewhat resembles that of the pear. According to Mouillefert it has all the qualities of hornbeam wood in a superior degree.

There is a fine specimen in the Botanic Garden at Oxford, which measures about 40 feet by 4 feet. This tree, though quite healthy, is much infested by mistletoe. At Tortworth there is a tree about 4o feet high by 2 feet 7 inches in girth, At Munden; Watford, a tree, 32 feet by 2 feet 11 inches, is said to have been planted about 1830.

In Scotland we know of no tree of this species of large size now existing, though a large one formerly grew at Bargally,^[8] a place between Gatehouse and Newton-Stewart, once the property of Andrew Heron, a celebrated planter, who died in 1729. Loudon went there in 1831, and gives the dimensions^[9] of the Ostrya

 

Plate 153: Hop-hornbeam at Langley Park, Norfolk

Plate 153.

HOP HORNBEAM AT LANGLEY PARK, NORFOLK

 

from a letter of the then owner, J. Mackie, as 60 feet high and 4 feet 1 inch in girth at 4 feet in 1835. Henry could find no trace of this tree when he visited Bargally in 1904. At Glasnevin, Dublin, there are two trees, 30 and 25 feet high, narrowly pyramidal in habit. These are 34 years old and are growing on the bank of a stream. (H.J.E.)

 

OSTRYA VIRGINICA, Ironwood, American Hop Hornbeam

 

Ostrya virginica, Willdenow, Sp. Pl. iv. 469 (1805); Loudon, Arb. et Frut. Brit. iii. 2015 (1838).

Ostrya virginiana, Koch, Dendrologie, ii. pt. ii. 6 (1873); Sargent, Silva N. Amer. ix. 34, t. 445 (1896), and Trees N. Amer. 192 (1905).

Ostrya Ostrya, Macmillan, Metaspermæ Minnesota Valley, 187 (1892).

Ostrya italica, sub-species virginiana, Winkler, Betulaceæ, 22 (1904).

Carpinus Ostrya, Linnæus, Sp. Pl. 998 (1753) (in part).

Carpinus virginiana, Miller, Dict. ed. 8, No. 4 (1768).

 

A tree attaining 60 feet in height and 6 feet in girth, but usually smaller. This species, as seen in cultivation, is mainly distinguished from Ostrya carpinifolia by the presence on the young branchlets, petioles, and midrib of the leaf beneath, of short, erect, gland-tipped hairs. The leaves (Plate 201, Fig. 9) are usually larger, 3½ inches long, slightly cordate at the base, with fewer nerves, about twelve pairs. The nutlet in this species is larger, ¼ to ⅓ inch long, fusiform, flattened, without a tuft of hairs at the apex, surmounted by a plainly visible calyx-limb.

Two forms of this species occur in the wild state, which have been distinguished by Spach,^[10] as follows:—

Var. glandulosa.—Young branchlets, petioles, and peduncles covered with gland-tipped short bristles. Specimens in the Kew herbarium from Ontario, Niagara Falls, and the Alleghany Mountains belong to this variety, which is the one known in cultivation in England.

Var. eglandulosa.—Glandular bristles not present on any part of the plant. Young shoots pubescent. This variety appears to be common in the western and southern: parts of the United States, and does not appear to have been introduced into cultivation. In the absence of fruit, it would be difficult to distinguish this variety from Ostrya carpinifolia. (A.H.)

The tree grows, according to Sargent, on dry gravelly slopes and ridges, often in the shade of oaks and other large trees; and is a native of Canada and the United States, occurring on the northern shores of Lake Huron in western Ontario, eastward through the valley of the St. Lawrence to Chaleur Bay and Cape Breton Island; extending southward to Northern Florida and Eastern Texas, and westward to Northern Minnesota, the Black Hills of Dakota, Nebraska, and Kansas. It is most abundant and of its largest size in Southern Arkansas and Texas.

I saw it at Mt. Carmel in Illinois, and in the Arnold Arboretum, where it was a finer tree in size and habit than Carpinus caroliniana. It is known in America as Ironwood, and is used for levers and tool handles, the wood being very tough and strong. Michaux states that on the estate of Duhamel du Monceau, in France, there were trees 20 feet high, from which self-sown plants had sprung up.

It was introduced into England by Bishop Compton in 1692, but is rarely met with except in botanic gardens. At Kew there are four trees, 20 to 30 feet in height. Others are growing at Eastnor Castle and at Grayswood, near Haslemere, where, though not planted above twenty years, it is growing vigorously, and looks as if it would make a handsome tree. A tree in the Edinburgh Botanic Garden was, in 1905, 39 feet high by 3 feet 3 inches in girth. Seedlings raised in my garden grow more freely than those of the common hornbeam; but not so fast as those of Ostrya carpinifolia. (H.J.E.)

 

OSTRYA JAPONICA, Japanese Hop Hornbeam

 

Ostrya japonica, Sargent, Garden and Forest, vi. 383, f. 58 (1893), Forest Flora Japan, 66, t. 22 (1894), and Silva N. Amer. ix, 32 (1896); Shirasawa, Icon. Ess. Forest. Japon, text 49, t. 25, ff. 1–14 (1900).

Ostrya virginica, Maximowicz, Mél. Biol. xi. 317 (1881).

Ostrya italica, sub-species virginiana, Winkler, Betulaceæ, 22 (1904).

 

A tree attaining in Japan a height of 80 feet, with a tall straight stem, 5 feet in girth, but usually smaller. This species is considered by Maximowicz and Winkler to be identical with the American species, and there is said to be little or no difference in the fruit, which I have not seen. In cultivation, the Japanese tree is readily distinguished as follows:—Leaves (Plate 201, Fig. 10) velvety to the touch on the upper surface, which is covered with a dense erect pubescence; nerves, ten to twelve pairs, fewer than in the other species; base slightly cordate. Young branchlets densely white pubescent, without glandular hairs, which are also absent from the petiole and midrib of the leaf.

According to Sargent, this species is nowhere abundant in Japan, occurring only as scattered individuals in the forests of deciduous trees which cover Central and Southern Yezo, and growing also in the province of Nambu in Northern Hondo. Shirasawa, however, gives a more extensive distribution, stating that it is found also throughout the central chain of Hondo, in the provinces of Musahi, Kai, and Totomi, and also at Nikko; and farther south, in the island of Shikoku. Ostrya waponica is also a native of China, being an exceedingly rare tree in the mountain forests of Eastern Szechwan and Western Hupeh, where it was discovered by Pére Farges and by myself. Ostrya mandschurica, Budischtschew,^[11] recorded from Manchuria, is probably identical with this species.

The Japanese Hop Hornbeam was introduced in 1888 into the Arnold Arboretum by seed sent from Japan by Dr. Mayr, and has proved hardy in the climate of Eastern Massachusetts. There are two trees at Kew, sent by Prof. Sargent in 1897, which are now about 15 feet high and growing vigorously. There is also a healthy young tree at Grayswood, Haslemere.(A.H.)

 

 

Plate 201: Carpinus and Ostrya; leaves, etc.

Plate 201.

CARPINUS AND OSTRYA.

 

1. Fliche, Bull. Soc. Bot. France, xlvi. 8 (1899). Cf. also 2d¢d. xxxv. 160 (1888).
2. Christ, Flore de la Suisse, 238 (1907). In the same work, p. 507, it is stated that this species has been found in the fossil state in miocene beds at Ardeche; and another species, probably a mere variety, has been found in the same strata at Var.
3. Arb. Nat. des Barres, 281 (1906).
4. Principales Essences Forestières, 148, note (1903). At Grignon in France, planted together in the arboretum, on calcareous soil with a chalky subsoil, at thirty years old the Hornbeam is 11 metres high by 70 centimetres in girth at 1 metre above the ground; and the Ostrya 11¹⁄₂ metres by 73 centimetres in girth. It bore here without injury the severe winter of 1879.
5. Op. cit. viii. 244 a.
6. Gard. Chron. viii. 275, Fig. 47 (1890). Also figured in Woods and Forests, 1884, p. 318. The shapes of the trees figured in Loudon and in the Gardeners' Chronicle are very different.
7. Kew Bull. 1897, p. 404.
8. Walker, Essays on Natural History and Rural Economy (1812).
9. Bargally is fully described by Loudon, op. cit. i. 95–99 (1838).
10. Ann. Sc. Nat. sér. 2, xvi. 246 (1841), and Hist. Vég. xi. 218 (1842).
11. In Trautvetter, Act. Hort. Petrop. ix. 166 (1884). I have seen no specimens of this.