Ulmus × viminalis

Ulmus × viminalis
Hybrid parentage U. minor × U. minor 'Plotii'
Origin England

Ulmus × viminalis Lodd. (:'willow-like elm'), occasionally referred to as the Twiggy Field Elm,[1][2] is a natural hybrid between U. minor and U. minor 'Plotii' which occurs in England where the two trees overlap. 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] though the name 'Plot's Elm' was later given by George Claridge Druce not to this hybrid but to one of its parents.[4] 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".[5]

U. × viminalis was once commonly treated as a variety of English Elm and listed as U. campestris var. viminalis, before it was determined as a hybrid by Melville.[6] A number of ornamental forms have been in cultivation since the 19th century (see Cultivars below).

Description

Trees of the U. × viminalis group vary in characteristics according to their U. minor parentage. Henry's "tree with ascending branches, pendulous branchlets, and sparse foliage" and Bean's "narrow-headed, rather slender tree" accord with what would be expected from a crossing of Plot Elm and Field Elm. Trees of the U. × viminalis group are slow-growing; they can ultimately reach 20 m in height.[3][7] Leaves vary 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.[8][3] See also Description under Cultivars (below).

Pests and diseases

Trees of the U. × viminalis group are very susceptible to Dutch elm disease. A specimen at the Ryston Hall , Norfolk, arboretum, obtained from the Späth nursery in Berlin before 1914,[9] was killed by the earlier strain of Dutch elm disease prevalent in the 1930s.

Cultivation

Cultivars of the U. × viminalis group (see below) have been introduced to continental Europe, North America and Australasia, where a few specimens survive in arboreta. Three trees, at different times labelled U. × viminalis and U. 'Viminalis' (but, from their shape, possibly 'Betulaefolia'), and pollarded in 1984,[10] stand in Benalla Botanic Gardens, Australia.[11] One tree, determined as U. viminalis Lodd by Melville, 40 feet (12 m) in height stood by lake at the Royal Botanic Gardens, Melbourne in 1953.[12]

Notable trees

A number of old non-ornamental U. × viminalis survive (2015) in a wood in Mepal, Cambridgeshire.[13]

Cultivars

Aurea, Betulaefolia, Gracilis, Incisa, Marginata, Pendula, Pulverulenta, Stricta, Viminalis.

Synonymy

Accessions

North America

Europe

Australasia

References

  1. ↑ Loudon, Arboretum et Fruticetum Britannicum, 3: 1378, 1838
  2. ↑ Inman, T. Frederic (1905). "The Elm". Proceedings of the Bath Natural History and Antiquarian Field Club. 10: 37. Retrieved 19 August 2016.
  3. 1 2 3 Elwes, Henry John; Henry, Augustine (1913). The Trees of Great Britain & Ireland. 7. p. 1906.
  4. ↑ Wilkinson, Gerald, Epitaph for the Elm, London 1978, p.72
  5. ↑ Melville, Ronald (1940). "Contributions to the study of British Elms:- III. The Plot Elm, Ulmus plotii Druce" (PDF). The Journal of Botany. 78: 181–191. Retrieved 13 June 2016.
  6. ↑ Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus" (PDF). Arnoldia. Arnold Arboretum, Harvard University. 24 (6–8): 41–80. Retrieved 20 June 2016.
  7. ↑ Browne, D. J. (1846). The Trees of America. Harper & Brothers, New York.
  8. ↑ Bean, W. J. (1988) Trees and shrubs hardy in Great Britain, 8th edition, Murray, London, p.659
  9. ↑ Ryston Hall Arboretum catalogue. c. 1920. pp. 13–14.
  10. ↑ vhd.heritage.vic.gov.au/vhd/heritagevic#detail_places;70863
  11. ↑ benalla.vic.gov.au/Files/BRC_Gardens_DL.pdf
  12. ↑ Muséum national d’Histoire naturelle, Paris (France). Collection: Vascular plants (P). Specimen P06882554
  13. ↑ Wilkinson, Gerald, After the Elm (London 1978)
  14. ↑ "List of plants in the {elm} collection". Brighton & Hove City Council. Retrieved 23 September 2016.
  15. ↑ Johnson, Owen (ed.) (2003). Champion Trees of Britain & Ireland. Whittet Press, ISBN 978-1-873580-61-5.
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