A tree 50 to 80 ft high, pyramidal when young, but ultimately forming a rounded or somewhat elongated head with the ends of the branches pendulous; trunk grey and often beautifully fluted; young shoots clothed more or less with pale hairs, which mostly soon fall away. Leaves oval or inclined to ovate, 11⁄2 to 31⁄2 in. long, 1 to 2 in. wide; the base rounded or heart-shaped, one side often longer than the other; short-pointed at the apex, unequally or doubly toothed; dark green and at first downy on the midrib above; under-surface more downy especially on the midrib and the ten to thirteen pairs of veins, both sides becoming nearly or quite glabrous by autumn; stalk 1⁄4 to 1⁄2 in. long. Male catkins 11⁄2 in. long. Fruiting catkins 11⁄2 to 3 in. long, furnished with large, conspicuous three-lobed bracts, the middle lobe 1 to 11⁄2 in. long, often toothed. They are produced in pairs facing each other, each with an ovate, ribbed nut at the base, 1⁄4 in. long.
Native of Europe and Asia Minor; indigenous to the south-east and east of England. A well-grown hornbeam is one of our handsomest trees, the foliage turning yellow in autumn; more graceful than the beech, for which many people mistake it. It is, of course, distinct in the duller, more conspicuously toothed leaves, and in the ridged or fluted trunk, and the fruiting arrangement is quite different. The timber is hard, almost bony, and is valued for making those intricate parts of the pianoforte which convey the movement from the key to the hammer that strikes the strings. Elwes describes it as 'the hardest, heaviest, and toughest' of our native woods. In earlier times hornbeams were largely coppiced and pollarded for the supply of firewood, as may be seen by the old pollards that cover so much of Epping Forest. Sir J. E. Smith says that this tree formed the principal part of that and other forests which once lay to the north and east of London. The hornbeam is a useful hedge plant, and hedges of it may often be seen in old-established nurseries, planted originally for shelter. Nearly all the hedges in the R.H.S. Garden at Wisley are of hornbeam. In this clipped state it retains its dead leaves until spring, like the beech.
The common hornbeam thrives well at Kew, where the largest is 70 ft high, with a girth of 121⁄4 ft. The tallest recorded in recent years is one at Studley Royal, Yorks., 90 × 81⁄2 ft (1958); this is perhaps the tree of which Elwes and Henry give a measurement of 75 × 61⁄2 ft in 1908. A hornbeam in Bitton churchyard, Glos., was planted shortly after 1817 by the father of Canon Ellacombe (1822-1916), who became rector there and made a famous garden which is frequently mentioned in this work. It measures 60 × 10 ft (1959); Elwes and Henry give 65 × 81⁄4 ft as its dimensions in 1908.
cv. 'Asplenifolia'. – Leaves deeply and regularly double-toothed, the primary teeth large enough to be called lobes. See also 'Incisa'.
f. carpinizza (Host) Neilr. C. carpinizza Host – A variety found in the south-eastern part of the range, e.g. in the Carpathians of Romania. It differs in the more distinctly heart-shaped base of the leaf and in the fewer (seven to nine) veins.
cv. 'Columnaris'. – A rather slow-growing tree, densely branched and leaved; spire-like when young, later egg-shaped, always with a central leader. Put into commerce by Späth's nurseries, around 1891.
cv. 'Fastigiata'. – This is the now established name for a hornbeam previously known as C. b. pyramidalis. The trees commonly grown under these names appear to be all of one clone, faster growing than 'Columnaris', conical when young but becoming more open and rounded with age. Two trees at Kew, both planted in 1894 but received from different nurserymen (one from Croux and the other from Hesse) are almost of the same size and girth (56 × 61⁄2 ft at 2 ft and 58 × 61⁄4 ft at 3 ft – 1966). A similar tree at Westonbirt measures 47 × 8 ft at 1 ft (1966). It was planted in 1929. There are reports of trees of 'pyramidal' habit occurring in the wild both in France and Germany.
cv. 'Heterophylla' – Similar to 'Incisa', but with some of the leaves more or less normal. The two are sometimes regarded as one and the same, but Kirchner, who grew both (Arb. Muscav., 1864), said they were distinct.
cv. 'Horizontalis'. – Discovered growing wild by M. Jouin of the Simon-Louis establishment near Metz and described by him as flat-topped, like Crataegus crus-galli.
cv. 'Incisa'. – With some similarity to 'Asplenifolia', this differs in having smaller and especially shorter leaves, coarsely and irregularly toothed, and only about six pairs of veins. There is little reason to doubt that this is an old clone, distributed early in the last century by Loddiges and by Booth of Hamburg (who had close trading relations) as C. b. incisa (or foliis incisis). It also agrees well enough with the original description of var. incisa by Aiton (Hort. Kew., 1789). Sometimes known, though in our view wrongly, as 'Quercifolia' (q.v.). A further complication is that the name 'Incisa' has also been used for the clone described above as 'Asplenifolia', but the latter is certainly not the incisa of Aiton nor of Loudon.
cv. 'Pendula'. – A weeping form; 'pendula dervaesii' is still more elegant.
f. quercifolia (Desf.) Schneid. – This name is founded on the var. quercifolia of Desfontaines, of which the description states merely that the leaves are oak-like. There are reports of trees in which some of the branchlets bear leaves which are smaller than in the type and with rounded lobes, and possibly it was such a tree that Desfontaines had in mind. The leaves of 'Incisa' (q.v.) are also somewhat oak-like, but the resemblance is to the leaves found on weak shoots of Q. cerris and the whole tree bears leaves of this type. The name C. betulus 'Quercifolia' (or C. b. quercifolia) has indeed been used, though wrongly it would seem, for 'Incisa'.
From the Supplement (Vol. V)
Mention was made on page 505 of the use of hornbeam as a hedging plant. At the Chateau de Beloeil in Belgium there are six miles of formal hornbeam hedges 20 ft high, their 11 acres of surface trimmed every year (Int. Dendr. Soc. Year Book 1972, p. 91).
specimens: Trent Park, Barnet, Middx., an ancient tree only 35 ft high but 121⁄2 ft in girth (1978); Speen House, Berks., 52 × 113⁄4 ft (1978); Borde Hill, Sussex, 50 × 121⁄2 ft (1985); Hurn Court, Hants, pl. 1740, 65 × 15 ft (1985); Wrest Park, Beds., 105 × 8 ft (1977); University Parks, Oxford, 70 × 101⁄4 ft (1981); Bath Botanic Garden, 80 × 101⁄4 ft (1978); Tatton Park, Cheshire, 90 × 9 ft (1983); Hutton-in-the-Forest, Cumb., 98 × 121⁄4 ft (1979); Lullingstone Park, Kent, with a split, burry trunk, 50 × 151⁄4 ft (1982).
cv. 'Fastigiata'. - specimens: Kew, 72 × 73⁄4 ft at 3 ft and 75 × 7 ft at 4 ft (1976); Rosebery Park, Epsom, Surrey, 56 × 41⁄4 ft and 52 × 43⁄4 ft (1981); West Dean, Sussex, in the Garden, 46 × 71⁄4 ft (1981); Westonbirt, Glos., 48 × 73⁄4 ft at 6 ft (1979); Colesbourne, Glos., pl. 1902, 85 × 51⁄4 ft (1984); Dyffryn Gardens, near Cardiff, 52 × 7 ft (1984); Abbeyleix, Co. Laois, Eire, 60 × 63⁄4 ft at 3 ft (1985).
C. caucasica Grossheim, separated from C. betulus as late as 1940, is recognised by some Russian botanists, and is said to range from the Caucasus to Anatolia and Iran. One differential character adduced is that its pollen-grains are only half the size of those of C. betulus. The name is given as a synonym of C. betulus in the new Flora of Turkey.