This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
No trace of the Common Elm has been found in ancient plant beds, though this cannot be said of the Wych Elm. The latter is thought to be native, the former not. The Common Elm does not usually set perfect seed, and is considered to be usually propagated by suckers. The roots reach a long way underground, 40 or 50 yds., and from these suckers are produced. The Wych Elm, however, is obtained from seedlings. The Common Elm is found as a native on the Continent, however, and is generally distributed throughout the Northern Temperate Zone in Central, Southern, and Eastern Europe, and West Asia, Siberia, and in N. Africa. In the British Isles the Common Elm is generally distributed, but it is not so widespread in Scotland, where it is usually planted, as indeed it is in England. It is found also in Ireland and the Channel Islands as a denizen. In Derbyshire it is found at an altitude of 1500 ft.
The habitat is hedges, hedgerows, woods, and fields. The Elm is often used as a boundary mark, and for avenues and parks in the country or town. To the writer are known lines of Elms called "The Twelve Apostles", and in many districts there are ancient Elms planted like Coronation Oaks and other trees to commemorate some national or local event of importance. The Common Elm, though frequently found in more upland habitats, occurs in the marsh formation in the Alder-Willow association. More frequent south of the Trent, it is more characteristic of the Lowlands than the Highlands.
The Elm has a characteristic habit. The main trunk is generally erect, branching" at some distance from the base. But lateral boughs commence at half its height, and there are thus two crowns, as it were, one above the other, with a gap between. There are many forms and varieties of the Common Elm, however, which differ in their habit. The species U. glabra has drooping branches like the Wych Elm. The trunk is, when full-grown, sometimes 125 ft. in height, and the girth as much as 20 ft., or even 30-40 ft.
The bark is grey, rugged, and often corky (U. suberosa, Ehrh.). The young branches are sometimes corky, The lower horizontal branches are often very large and as much as 30-40 ft. long, sometimes becoming too bulky and snapping asunder. They may spring from the bole at about 10 ft. from the ground, or at a height of 15-20 ft. The leaves are oblique, unequal at the base, smaller than in the Wych Elm, not much longer than broad, rough above, stellately downy in the axils of the veins below. The margin is coarsely toothed, and the leaf ends in a long, blunt point.
The veins form a fork at the margin, and are deeply impressed on the upper surface, prominent below. The main branches ramify into numerous smaller branches, and these into twigs turned up at the end, lace-like in outline. The bole is stout and erect, with stout buttresses in old trees. The buds are dull brown, with many scales, each being really a pair of stipules, the lowest pair not lengthening in spring, There are several enclosing the leaf-bud within. The outermost scales serve to protect the inner from cold in winter. A pair of scales protects the leaves, and they are united to the base of the stem each side of the leaf-stalk. The scales fall at length. The leaf is folded up in bud upon the midrib. It is closed up in a fan-like manner on the lateral veins.
The flowers are not borne in catkins as in the other trees which belong to the Amentiferae, but are in tufted clusters. The perianth is cup-like, 4-5-fid, the lobes fringed with hairs, and contains five or four stamens with purple anthers, and a central pistil. There are two chambers in the ovary, but only one develops, and that rarely matures. The flower-stalk is short. The flowers appear before the leaves. They are vinous-red in colour. The fruit is an inversely ovate, or elliptic-oblong samara, notched, with the seed above the centre and near the notch. There is a wing all round the seed except at the notched apex, the lobes of the notch being incurved. The samara is greenish-brown or brown.
The Common Elm flowers in March, and is a deciduous tree.
Most trees are pollinated by the wind, and it is supposed that this mode of pollination is the most primitive. However this may be, the trees usually flower before the leaves are in bud, and have the parts of the flower especially modified to this end.
The Elm has usually hermaphrodite or complete flowers, but may be sometimes monoecious. The perianth is a bell-shaped structure with a variable number of teeth, or segments, and tubular below. It is hairy on the lower part, and the teeth are sparingly glandular. The pistil lies in the centre surmounted by a bifid stigma, with papillae on the inner face and pectinate glandular structures or hairs. There are as many stamens as perianth-lobes. The stigma is usually said to ripen before the anthers, as is usually the case in wind-pollinated flowers, but sometimes the anthers ripen first. There are 2 anther-cells, and they open outwards. Soon after the stigma matures the anther-stalks lengthen, and if the stigma be still receptive, pollen falling on the stigmas, the flower will be self-pollinated. In the ordinary course pollen is blown upwards to another flower on the same tree. When the anthers have withered the style lengthens and the stigma protrudes from the perianth, in which it was at first included. In spite of its adaptation to cross-pollination by the wind the Common Elm does not, in England, set perfect seed as a rule. Personally, the writer is inclined to attribute this to a tendency to self-pollination which seems not to have been generally noticed, especially when proterandry occurs and is not well marked. The fruit or samara is dispersed by aid of the wind, the broad wing serving this end.
Though generally planted, the Elm appears to flourish best in loamy or clayey soil, and if grown on sandy soil the horizontal roots are often exposed to the weather and to frost, and the tree is liable to die off in the upper part during drought, or from exposure of the roots.
The Elm is liable to the attacks of fungi, similar to those that infest the Wych Elm, as Taphrina ulmi, Mycosphcerella ulmi (Elm leaf spot), Psilocybe spadicea, Hypholoma fascicularis, Flammula ulmicola, Pholiota adiposa, Pleurotus ulmarius, Collybia velutipes, Forties fomen-tarius; Tinder fungus, Hydnum diversidens; Oak rot, Phleospora ulmi; galls such as Schizoneura ulmi, Pemphigus pallidus; the moths, Wood Leopard, Lime Hawk-moth, Copper Underwing, Common Dagger, Small Engraved Moth; the butterflies, Large Tortoise-shell, Comma, White-letter Hairstreak; the beetles, Orchestes alni, Scolytus destructor, S. multistriatus, Hylesinus vittatus, Epipeda plana, Quedius ventralis, Ocypus fuscatus, Trichonyx sulcicollis, Symbiotes latus, Endonychus coccineus, Dacne humeralis, Cerylon histeroides, Lcemophloeus ater, Mycetophagus populi, Teresias serra, Dorcus parallelipedus, Ischnodes sanguinicollis, Haplocnemus impressus, Rhagium inquisitor. The He-miptera Heteroptera, Brachysteles parvicornis, Phytocoris ulmi, Ortho-tylis viridinervis, 0. ochrotrichus, 0. prasinus, Malacocoris chlorizans, Asciodema fieberi are found on Elm. The following Hemiptera Homoptera, also infest the Elm: Pediopsis ulmi, Allygius commutatus, Alebra albo-striella var. Wahlbergi, Typhlocyba ulmi, T. lethierryi. A Hymenopterous insect, Psen pallipes, is found on it.
The names by which the Elm is known are numerous, viz.: Allom-tree, Alme, Aum, Elem, Ellem, Elm, English Elm, Elmen, Elven, Helm, Horse May, May, Ome Tree, Owm. The name Elm is apparently cognate with the Latin Ulmus, a Plinyan name for the Elm, and Ellum is a general name for Elm. The corky type, Ulmus suberosa, is called All-heart.
Called in some districts Elven, the Elm seems to have been considered to have had some connection with fairies. The name May is applied to a piece of Elm gathered early in the morning of the first day of the month. The Elm in Devonshire is regarded as one of those trees which are not liable to be struck by lightning, but this is not generally the case.
Agricultural operations have been guided in the past by the time when the tree is in leaf, as is illustrated by the following lines: " When the Elmen leaf is as big as a mouse's ear, Then to sow barley, never fear; When the Elmen leaf is as big as an ox's eye, Then say I ' Hie! boys, hie!'"
A variety with broad leaves in Cornwall is called Horse May.
The Elm is a useful timber tree. Not only is the hard wood or brown heart used but also the sapwood. Water-pipes were once made of hollow Elm. The wood is durable and resists the action of water well, being employed for pumps, keels, bilge-boards on ships. It is also used for furniture and chairs.
Essential Specific Characters: 277. Ulmus campestris, L. - Tree, erect, branches ascending, leaves ovate, dentate, asperous, flowers 4-5-fid, seed above middle of samara, near the notch.