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''Ulmus davidiana'' var. ''japonica'', the Japanese elm, is one of the larger and more graceful Asiatic elms, endemic to much of continental north-east Asia and Japan, where it grows in swamp forest on young alluvial soils, although much of this habitat has now been lost to intensive rice cultivation.〔Makita, H., Miyagi, T., Miura, O., and Kikuchi, T. (1979). A study of an alder forest and an elm forest with special reference to their geomorphological conditions in a small tributary basin. In: Vegetation und Lansdschaft Japans. ''Bull: Yokohama Phytosoc. Soc. Japan'' 16, 1979〕 ==Description== The size and shape of the Japanese elm is extremely variable, ranging from short and bearing a densely branched broad crown similar to the Wych elm to tall, single-stemmed, with narrow crown similar to the English elm Augustine Henry described one of the latter outside Iwamigawa, Hokkaido, railway station as being 34 m tall, with a clean stem to a height of approximately 15 m. 〔Elwes, H. J. & Henry, A. (1913). ''(The Trees of Great Britain & Ireland )''. Vol. VII. 1848–1929. Republished 2014 Cambridge University Press, ISBN 9781108069380〕 The young shoots often bear corky wings, similar to those of the European field elm ''U. minor'', to which it is closely related. The leaves are generally obovate, < 11 cm long, and with a coarse upper surface. Like many of the European field elms, var. ''japonica'' retains its green foliage well into the autumn, before a late display of deep yellow. The perfect, apetalous wind-pollinated flowers emerge in early spring, before the leaves. The samara, <15 mm long, is obovate to orbicular, occasionally hairy over its entire surface but more often glabrous.〔〔Fu, L., Xin, Y. & Whittemore, A. (2002). Ulmaceae, in Wu, Z. & Raven, P. (eds) ''Flora of China'', Vol. 5 (Ulmaceae through Basellaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, USA ()〕 Trees grown from seed at Great Fontley in southern England first flowered aged 13 years.〔Brookes, A. H. (2015). ''Great Fontley Elm Trial, 2015 Report''. Butterfly Conservation, Hants & IoW Branch, England. 〕 File:Japanese elm.jpg|Japanese elm, showing pendulous habit of lower branchlets. SHHG, Romsey, UK File:Japanese elm leaves.jpg|Japanese Elm leaves File:Hokkaido University - Library.jpg|Autumn colouring of Japanese Elm, Hokkaido University Botanical Gardens, Sapporo (November 2013)〔Labelled 'Forest Elms' by photographer (663highland) on Hokkaido University page〕 File:131103 Hokkaido University Sapporo Hokkaido Japan10s5.jpg|Autumn colouring of Japanese elms, Hokkaido University Botanical Gardens File:HokkaidoDaigakuSapporoKyanpasuSeimon2005-2.jpg|Elms at main gate of the Sapporo Campus of the Hokkaido University File:131103 Hokkaido University Botanical Gardens Sapporo Hokkaido Japan04s3.jpg|Old tree in Hokkaido University Botanical Gardens, Sapporo (November 2013) 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 davidiana var. japonica」の詳細全文を読む スポンサード リンク
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