Ulmus × viminalis

Ulmus × viminalis

Ulmus × viminalis, Easton, Cambridgeshire (2015)[1]
Hybrid parentage U. minor × U. minor 'Plotii'
Origin England

Ulmus × viminalis Lodd., occasionally referred to as the Twiggy Field Elm, is an elm hybrid derived from the crossing of U. minor and U. minor 'Plotii'. Bean said that the cultivar, which he called Ulmus 'Viminalis', is one form of a natural hybrid, U. × viminalis, which occurs from Essex to Oxfordshire.[2] According to Henry, this was the tree first described in 1677 by Robert Plot from specimens growing in an avenue and coppice at Hanwell near Banbury,[3][4] though the name 'Plot's Elm' was later given by George Claridge Druce not to this hybrid but to one of its parents.[5] However, writing in 1940 and referring to a pencil rubbing in Herb. Druce, vol. 113 of the Sloane Collection, Melville questioned Henry's claim. "I can see no reason to doubt that this is Plot's plant", but "it is [not] U. × viminalis Lodd".[6]

The tree was once commonly treated as a variety of English Elm before it was determined as a hybrid by Melville.[7]

Description

Leaves of U. 'Viminalis', Benalla Botanic Gardens, Australia

Bean's description, "a narrow-headed, rather slender tree", and Henry's "tree with ascending branches, pendulous branchlets, and sparse foliage", accord with what would be expected from a crossing of Plot Elm and Field Elm. Ulmus × viminalis is a slow-growing tree which can ultimately reach 20 m in height.[3][8] Leaves vary according to U. minor parentage, from obovate-elliptic to narrowly elliptic; they are deeply serrated, < 5.0 cm long, nearly symmetrical at the base and long-acuminate at the tip, with prominent white axil tufts on the undersides.[2][3] The cultivar form can be mistaken for a variety of birch;[8] the tree has also been likened to Zelkova × verschaffeltii.[9]

Pests and diseases

The cultivar is very susceptible to Dutch elm disease; a specimen at the Ryston Hall , Norfolk, arboretum, obtained from the Späth nursery in Berlin before 1914,[10] was killed by the earlier strain of Dutch elm disease prevalent in the 1930s.

Cultivation

Two pollarded U. 'Viminalis', Benalla Botanic Gardens, Australia (2006)

A few specimens survive in arboreta in the UK, USA, and Australia.

Notable trees

Two trees, pollarded in 1984,[11] stand in Benalla Botanic Gardens, Australia.

Cultivars

Aurea, Betulifolia, Marginata, Pulverulenta.

Synonymy

Accessions

North America

Europe

Australasia

References

  1. ↑ Determined by Coleman (2000), sample no. 5, as Ulmus × viminalis. plot-elms.co.uk/home/cambridgeshire-plot-elms
  2. 1 2 Bean, W. J. (1988) Trees and shrubs hardy in Great Britain, 8th edition, Murray, London, p.659
  3. 1 2 3 Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland. Vol. VII. p.1906. Private publication. Republished 2014 Cambridge University Press.
  4. ↑ http://fax.libs.uga.edu/QK488xE4/7tgbi/
  5. ↑ Wilkinson, Gerald, Epitaph for the Elm, London 1978, p.72
  6. ↑ Melville, Ronald, ''The Journal of Botany'', London, Vol.78, Aug. 1940
  7. ↑ Green, P. S. (1964). Registration of cultivar names in Ulmus. Arnoldia, Vol. 24. Arnold Arboretum, Harvard University.
  8. 1 2 Browne, D. J. (1846). The Trees of America. Harper & Brothers, New York.
  9. ↑ Hilliers' Manual of Trees & Shrubs. (1977). David & Charles, Newton Abbot, UK.
  10. ↑ Ryston Hall Arboretum catalogue, circa 1920
  11. ↑ vhd.heritage.vic.gov.au/vhd/heritagevic#detail_places;70863
  12. ↑ Johnson, Owen (ed.) (2003). Champion Trees of Britain & Ireland. Whittet Press, ISBN 978-1-873580-61-5.
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