A large tree with an open, ascending, broad-oval crown which will eventually become round. The European white elm can grow to over 30 m and just as wide. The year-old twigs are brown-green and hairy and the old bark is grey and finely grooved. Its roots form distinct buttressing at the base of the trunk. The glossy dark green leaf is markedly asymmetric although the autumn colours are not very spectacular: usually slightly yellow. The flowers are red and the fruit often has a reddish hue too. Until recently, this inherently European species received little attention until it emerged that Ulmus laevis is only sporadically attacked by Dutch elm disease. The tree is not particularly resistant, but the elm bark beetle, that is responsible for spreading the disease, appears to avoid the tree. A lovely imposing tree for planting in parks and landscapes.
Ulmus laevis Pall., variously known as the European white elm, fluttering elm, spreading elm, stately elm and, in the United States, the Russian elm, is a large deciduous tree native to Europe, from France northeast to southern Finland, east beyond the Urals into Kyrgyzstan and Kazakhstan, and southeast to Bulgaria and the Crimea; there are also disjunct populations in the Caucasus and Spain, the latter now considered a relict population rather than an introduction by man, and possibly the origin of the European population. U. laevis is rare in the UK, although its random distribution, together with the absence of any record of its introduction, has led at least one British authority to consider it native. NB: The epithet 'white' elm commonly used by British foresters alluded to the timber of the wych elm.
Ulmus laevis is similar in stature to the wych elm, if rather less symmetric, with a looser, untidy, branch structure and less neatly rounded crown. The tree typically reaches a height and breadth of > 30 m, with a trunk < 2 m d.b.h. The extensive shallow root system ultimately forms distinctive high buttresses around the base of the trunk. The bark is smooth at first, then in early maturity breaks into thin grey scales, which separate with age into a network of grey-brown scales and reddish-brown underbark, and finally is deeply fissured in old age like other elms. The leaves are deciduous, alternate, simple ovate with a markedly asymmetric base, < 10 cm long and < 7 cm broad, comparatively thin, often almost papery in texture and very translucent, smooth above with a downy underside. Significantly, the leaf veins do not divide from the central vein to the leaf margin. The leaves are shed earlier in autumn than other species of European elm.
The tree is most reliably distinguished from other European elms by its long flower stems, averaging 20 mm. Moreover, the apetalous wind-pollinated flowers are distinctively cream-coloured, appearing before the leaves in early spring in clusters of 15-30; they are 3–4 mm across. The fruit is a winged samara < 15 mm long by 10 mm broad with a ciliate margin, the single round 5 mm seed maturing in late spring. The seeds have a generally high rate of germination, 45–60% for Serbian trees examined by Stilinović.
Although the species is protandrous, levels of self-pollination can be high The tree can grow very rapidly; where planted in persistently moist soil, trunk width of 13-year-old trees increased by 4 cm per annum at breast height (d.b.h.). The species differs from its closest relative, the American elm, mainly in the irregular crown structure and frequent epicormic shoots, features which also give the tree a distinctive winter silhouette. The American elm also has less acute leaf buds, longer petioles, narrower leaves, and a deeper apical notch in the samara which reaches the seed.