|
''Ulmus minor'' 'Stricta', a member of the Field Elm group known as the Cornish Elm, was commonly found in South West England, Southern Ireland and Brittany until the arrival of Dutch elm disease in the late 1960s. Dr Max Coleman of Royal Botanic Garden Edinburgh, arguing in his 2002 paper on British elms that there was no clear distinction between species and subspecies, suggested that known or suspected clones of ''Ulmus minor'', once cultivated and named, should be treated as cultivars, preferred the designation ''U. minor'' 'Stricta'. The DNA of 'Stricta' has been investigated and the cultivar is now known to be a clone.〔Coleman M. (2002) 'British elms.' ''British Wildlife'' 13 (6): 390-395.〕 Mature trees are now largely restricted to Australia, whither it was introduced in the 19th century. ==Description== Growing to a height of up to , the Cornish Elm is a slender, slow-growing deciduous tree, distinguished by its long, straight trunk, which culminates in a narrow fan-shaped crown comprising short, straight, ascending branches.〔(Diagnostic photographs of Cornish elm in St Austell (Francis Frith Collection) ); at Coldrenick, Menheniot ((Elwes and Henry, ''The Trees of Britain and Ireland'' vol.VII, Plate 397 ) (p.1933 )) ; in Zelah ((oldcornwall.netfirms.com) ).〕 The leaves are small, obovate to oval, typically acuminate at the apex, 6 cm long by 3.5 cm broad, with a dark-green upper surface, glossy and smooth. The perfect apetalous wind-pollinated flowers occur in clusters of 15–20 on very short pedicels. The samarae rarely ripened in England, but when mature were very similar to those of others in the Field Elm group, being mostly obovate, 16 mm long by 10 mm broad. Dr Oliver Rackham (1986) noted that Cornish Elms with "more spreading" crowns grow around Truro and on the Lizard Peninsula, illustrating the variety, which he called 'Lizard Elm', with a 1980 photograph.〔Rackham, Oliver, ''The History of the Countryside'' (London, 1986), p. 236〕 File:Cornish Elm 2008.JPG|Cornish Elm in Preston Park, Brighton, 2005 File:Cornish Elms at Coldrenick.jpg|''U. minor'' 'Stricta', Coldrenick, Cornwall, before 1913 File:Ulmus minor 'Stricta' leaves.jpg|Leaves of Cornish Elm, Penhalvean, Cornwall 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 minor 'Stricta'」の詳細全文を読む スポンサード リンク
|
