Ulmus procera

The English elm is the finest of several varied forms that, before the disastrous epidemic of Dutch elm disease in the 1970s, could be found across the lowland plains of southern England and the Midlands. As a group they are called 'Field elms' because they occur in hedgerows between fertile agricultural fields. The causes of the variability still puzzle the experts. One possibility is the natural spread of certain continental elms to south-east England while the land bridge with France still existed. These European species, which are themselves variable, may later have spread slowly north and west, hybridising between themselves and with the well-established native Wych elm, to give local races. Another theory is that the English elm was deliberately brought over by Iron-Age tribes, to provide timber and also fodder for livestock. In some Eastern countries elms are lopped annually as a source of catde food, and goat-keepers still make occasional use of elm foliage even in Britain.

As a rule, the seed of these lowland Field elms has only a low degree of fertility, if any. In practice they are increased by separating sucker shoots from their parent roots, by layering branches, or by grafting. This means that any peculiar kind of elm is repra-

Dutch Elm Winter Twigs

figure in

Winter twig of English elm. showing fine branching, and small growth buds with larger flower buds (xf). Single bud (X6).

duced exactly, as a 'done' or 'cultivar.' identification by means of small specimens, such as a few leaves or shoots, is difficult, because elm leaves vary a great deal in shape, size, and hairiness, even on the same tree. Leaves from vigorous sucker shoots, for example, are usually far larger than others, and maybe a different shape. But when the whole tree is seen it is often possible to assign it to a particular sort, as its habit of growth will'aid the impressions given by the smaller portions. Figure 115 shows characteristic crown patterns for a few common kinds.

These lowland or Field elms are probably not found growing

Ulmus Procera

wild or even in pure woods established artificially. They nearly always grow along hedgerows, or else in small spinneys or on patches of rough ground where hedgerows meet. The network of hedges that runs right across the landscape is artificial in origin, having been formed during the great Enclosure Movement, largely in the J8th century. A high proportion of the elms we see today is descended, as suckers, from the trees planted by the landowners and farmers who made the original enclosures. These parent elms were often set out at the same time as the first hawthorn bushes that made up the hedges.

English Elm Fruit

FIGURE 114

Leafy twig of English elm, with typical hairy surfaces, and small, randomly set leaves; note the small fruits (XlJ). Single fruit (X4).

FIGURE 114

Leafy twig of English elm, with typical hairy surfaces, and small, randomly set leaves; note the small fruits (XlJ). Single fruit (X4).

John Evelyn, who is regarded as the father of British forestry, described five methods of propagating elms by vegetative means in his Silva, published in 1664. Further details were contributed by Alexander Hunter in his 1776 edition of the same book. These authors make it dear that the large-scale raising of elms, from foundation stocks maintained by nurserymen, was a well established practice from about 1625 to 1775; later records show that it was continued for a further 100 years. This explains why the elms in a particular district often look remarkably similar -they came from the same nursery and the same parent stock. It also accounts for the occasional appearance of a few 'unusual' elms in a particular place, since planting or propagating material could readily be sent over long distances. Landowners with two or more estates - a common situation - would often use their best available elm on both. One landowner. 'Planter John,' Duke of Montagu (died 1749), planted I15km of elm avenues across Northampton shire.

The English elm is usually given specific status, as Ulmus procera Salisbury. There is no elm quite like it on the Continent; in fact this, and a few other peculiar regional elms and whltebeams, are the only trees unique to Britain.

English elm was found over most of the English Midlands, alone or in association with other kinds. The Severn valley was its stronghold and it may have arisen there.

The twigs of English elm are hairy and slender, with a typically zig-zag habit of growth; the buds, which are also hairy, are small. The leaves are small and oval, and have a roughly hairy upper surface. Seeds and wings are likewise distincdy smaller than those of Wych elm. The bark on the trunk is thick and furrowed into ridges which are broken into blocks. Suckers spring up abun-dandy from the roots of old trees or those killed by Dutch elm disease, but seed is rarely fertile. Suckers that spring in fields are either eaten by livestock or cut up by ploughs; only those that come up along the hedge itself can survive.

English elm has a magnificent habit of growth, which cannot be matched elsewhere; it added a characteristic note to the landscapes of England's vales. The trunk is stout and erect growing far taller than any associated tree, and from it there extend great billowing clouds of foliage, borne on distinct branch groups. Growth is rapid, and elms were righdy planted, preserved, or encouraged to grow from suckers along the hedgerows as a profitable source of timber. Records for height are 43m, and for girth 7.62m, though today no tree taller than 36.5m can be found. Propagation today is usually effected by using softwood cuttings, using mist in summer.

Between 1930 and I960 all our elms were seriously threatened by the Dutch elm disease, caused by the fungus Ceratocystis uhni which is carried from tree to tree by the Small elm bark beetle Scolytus scolytus. This spread rapidly at first, but the surviving elms appeared resistant to it. Unfortunately a catastrophic outbreak occurred in the 1970s and this has led to the recommendation that only resistant strains of elms should be used for future planting.

Ordinary elms should not be planted in places such as parks that are much frequented by the public, since they are apt -though only occasionally - to shed large branches without warning. Narrow-crowned elms, such as the Cornish elm, described on the following pages, are free from this danger.

Flowers of English elm are illustrated in Figure 118, seeds in Figure 114, and leaves in Figure 119-

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