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''Ulmus'' × ''hollandica'' 'Major' is a distinctive cultivar that in England came to be known specifically as ''the'' Dutch Elm, although all naturally occurring Field Elm ''Ulmus minor'' × Wych Elm ''U. glabra'' hybrids are loosely termed 'Dutch elm' (''U.'' × ''hollandica''). It is also known by the cultivar name 'Hollandica'. A native of Picardy and northern France, where it was known from the fifteenth to nineteenth centuries as ''ypereau'' or ''ypreau'',〔Richens, R. H., ''Elm'' (Cambridge, 1983), p. 53-54 also 33, 42.〕 the tree was introduced to England from the Netherlands in the late seventeenth century as a fashion-elm associated with William & Mary,〔Rackham, O. (1976). ''Trees and Woodland in the British Landscape'' J. M. Dent, London.〕 the name 'Dutch Elm' having been coined by Queen Mary's resident botanist Dr Leonard Plukenet.〔Armstrong, J. V. & Sell, P. D. (1996). A revision of the British elms (''Ulmus'' L., Ulmaceae): the historical background. ''Bot. J. Linn. Soc.'' 120: 39-50.〕 The epithet 'Major' was first adopted by Smith in Sowerby's ''English Botany'' 36: t. 2542, published in 1814, identifying the tree as ''Ulmus major''. Krüssmann formally recognized the tree as the cultivar ''U. × hollandica'' 'Major' in 1962 〔Krüssmann, G. (1962). ''Hand. Laubgeh.'' 2: 537.〕 ==Description== In areas unaffected by Dutch elm disease, 'Major' often attains a height of > 30 m, with a short bole and irregular, wide-spreading branches. In open-grown specimens, the canopy is less dense than that of the English elm or Wych elm. The bark of the trunk is dark and deeply fissured and, like English elm, forms irregular 'plates' in mature specimens, serving to distinguish it from the Huntingdon Elm (latticed bark), the other commonly planted ''U. × hollandica'' in the UK.〔Mitchell, A. (1974). ''A Field Guide to the Trees of Britain & Northern Europe''. Collins, London. ISBN 0-00-219213-6〕 The leaves are oval, < 12 cm long by 7 cm wide, the top surface dark green and glossy, with a long serrated point at the apex.〔(Photograph of 'Major' leaves, ulmen-handbuch.de )〕 The red apetalous, perfect, wind-pollinated flowers are produced in spring in large clusters of up to 50. The obovate samarae are up to 25 mm long by 18 mm broad. The cultivar may be distinguished from other elms by the corky ridges which on mature trees occur only on the epicormic branches of the trunk. On immature trees and suckers, the corky bark is more pronounced. The seed is rarely viable, but the tree suckers profusely from roots.〔Richens, R. H. (1983). ''Elm''. Cambridge University Press.〕〔Bean, W. J. (1981). ''Trees and shrubs hardy in Great Britain'', 7th edition. Murray, London.〕〔Elwes, H. J. & Henry, A. (1913). ''The Trees of Great Britain & Ireland.'' Vol. VII. pp 1848-1929. Private publication. ()〕 In the south of Britain, 'Major' is commonly found as a sucker, sometimes in mixed hedgerows with English Elm. Large Dutch Elm sucker-populations have been found in south west Wales, Cornwall and along the south coast of England. The suckers of Dutch Elm are sometimes confused with those of English Elm, which may explain the widespread and random occurrence of the former in hedgerows in southern Britain. 'Major' comes into leaf some three weeks later than English elm, and loses its leaves some three weeks earlier,〔Elwes, H. J. & Henry, A. (1913). ''(The Trees of Great Britain & Ireland )''. Vol. VII. 1848–1929. Republished 2004 Cambridge University Press, ISBN 9781108069380〕 and when young, its branching is straighter, stouter and more open. It is usually more vigorous than English elm. The larger, tapering leaves, predominantly corky bark, and bold herringbone outline of Dutch Elm suckers also help to distinguish them from those of English elm. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ulmus × hollandica 'Major'」の詳細全文を読む スポンサード リンク
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