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''Ulmus'' 'Nanguen' (selling name ) is a complex fourth generation hybrid cultivar from the cross 'Plantyn' × (''Ulmus × hollandica'' 'Bea Schwarz' selfed), an ancestry comprising four Field Elms ''U. minor'', two Wych Elms ''U. glabra'', the curious Exeter Elm, 'Exoniensis', and a frost-resistant selection of the Himalayan Elm ''U. wallichiana''. Originally identified as clone 812, was not promoted by the Dutch owing to unfounded fears that it may prove susceptible to Coral Spot fungus ''Nectria cinnabarina''. Instead, '812' was acquired by the French Institut National de la Recherche Agronomique (INRA), which subjected the tree to 20 years of field trials in the Bois de Vincennes, Paris, before patenting and release in 2002 as 'Nanguen' = .〔SAPHO. ''Ulmus'' 'Nanguen' = , (), La Menitre, France.〕〔Department of Forest Health, ''Forest Health in France 2002'' (), Paris, France.〕 ==Description== The stem of typically forks at a height of between 1 and 2 m, where 3 to 5 steeply ascending branches develop in conjunction with more obtusely angled lower side branches to form an amorphous open crown. The ultimate size and shape of this cultivar remains unknown but, given its ancestry, it should reach at least 30 m in height. The trees planted in the Bois de Vincennes attained an average height of 12.5 m with a trunk diameter of 22 cm at 20 years of age.〔Pinon, J. 2007). ''Les ormes résistants à la graphiose'' (:Elms resistant to Dutch Elm Disease). Forêt-entreprise, No. 175 - Juillet 2007, p 37-41, IDF, Paris, France. http://www.foretpriveefrancaise.com/data/info/127219-P.pdf〕 Quick growing on moist, well-drained soils, increasing in height by an average of 80 cm per annum, the tree commences flowering in late March when aged seven years. is most reliably identified by the shape and colour of its leaves; elliptic to orbicular < 11 cm long × 9 cm wide, the acuminate apex far less pronounced than in most other elms, and coarse, doubly serrate margins. The upper surface is rough, and bright grass-green in colour. The leaves flush relatively late, rarely before May in England. The samarae are obovate, slightly notched at the outer end, 14 – 22 mm long by 11 – 17 mm broad. The seed is not central but slightly nearer the notch, and ripens in late May.〔Brookes, A. H. (2015). ''Disease-resistant elms, Butterfly Conservation trials report, 2015'' Butterfly Conservation, Hants & IoW Branch, England. ()〕 Image:Lutece leaf 2.jpg| leaf in August. Image:Ulmus LUTECE samarae.jpg| samarae. Image:WLH Julita.JPG|White-letter Hairstreak on , Sweden. Image:LUTECE Towngate Newport 2.jpg| on IoW, hosting White-letter Hairstreak 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 'Nanguen' = Lutece」の詳細全文を読む スポンサード リンク
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