''Ulmus'' 'Purpurea'

Ulmus 'Purpurea'
Genus Ulmus
Cultivar 'Purpurea'

The elm cultivar Ulmus 'Purpurea' K.Koch (1872),[1] the Purple-leaved Elm, may be synonymous with the Ulmus Stricta Purpurea, the 'Upright Purpled-leaved Elm', listed and described by John Frederick Wood, F.H.S., in The Midland Florist and Suburban Horticulturist (1851).[2] The Späth nursery in Berlin, in its late 19th and 20th-century catalogues, listed both an U. montana atropurpurea (raised there c.1881)[3][4][5] and an U. campestris purpurea,[4][5] distributing them as separate cultivars.[6][7] Späth, like many of his contemporaries, used U. montana both for wych elm cultivars and for those of U. × hollandica, while his U. campestris were usually field elm clones. Henry (1913) listed U. montana var. atropurpurea, as a wych elm variety, and Ulmus campestris var. purpurea Petz. & Kirchn.,[8] adding that the latter, grown at Kew as U. montana var. purpurea, was "probably of hybrid origin".[9] His description of Kew's U. montana var. purpurea matches that of the commonly-planted 'Purpurea' of the 20th century (see below). His discussion of it (confusingly) under U. campestris, his name for English Elm, may be the reason why 'Purpurea' is sometimes erroneously called U. procera 'Purpurea' (as in USA and Sweden; see 'Cultivation' and 'Accessions').

The ancestry of 'Purpurea' thus remains obscure, but the fact that it very occasionally produces suckers suggests a hybrid origin with some U. minor component. F. J. Fontaine conjectured U. glabra × U. minor 'Stricta' [10] and placed the tree in the U. × hollandica group under the name U. × hollandica 'Purpurascens'.[11][10] The samarae, leaves and the habit of 'Purpurea' appear to support this conjecture.

U. glabra itself occasionally produces red- or purple-flushed new leaves.[12] There is also a small-leaved elm U. minor 'Purpurascens' (Ulmus 'Myrtifolia Purpurea'), which Späth again listed and distributed separately from his U. campestris purpurea.[4][6]

In North America, purple-leaved elms encountered in the fall are likely to be the new hybrid Ulmus 'Frontier'.

Description

Of U. Stricta Purpurea Wood wrote (1851): "When young, the foliage is dark purple, in the way of the Purple Beech. As the season advances, it becomes somewhat greener, but always retains a distinct and peculiar character."[2] U. purpurea K.Koch had "leaves purple when young, changing to dark green". 'Purpurea' grows to > 25 m in height, and is short-trunked with open, straggling, ascending branches. The bark has a reddish-brown hue. The leaf-buds are long, sharply pointed and dark purple, on shoots of the same colour. The flowers, too, emerge a uniform dark purple. The fruit, tinged purple over the seed, is intermediate between U. glabra and U. minor. The leaves, which are slightly folded, have a brief purplish-green flush in spring. The new leaves of lower bole-shoots and of suckers are pure dark purple, without any green.[13][14][15] After the spring flush, the leaves become olive green then darken in the summer - perhaps the darkest green of all the elms. Their underside is paler, so that, with their increasing fold as the year progresses, the late-summer foliage has a greyish hue.[16]

Pests and diseases

The tree is susceptible to Dutch elm disease.

Cultivation

In Australia cultivars by the name of U. glabra 'Purpurea', U. procera 'Purpurea' and U. purpurea appear in old nursery catalogues dating from 1882;[17] these are now believed to be synonymous with the clone still in cultivation there as U. × hollandica 'Purpurascens'.[18][19] 'Purpurascens' was sold by Searl's Garden Emporium, Sydney at the beginning of the 20th century and was "quite widely" planted in the south-east of the country, where it is said to tolerate dry conditions.[20] Urban plantings include avenue specimens and scattered trees in Fawkner Park, Melbourne.[21][22] This cultivar appears to be the same clone as the U. montana atropurpurea supplied by the Späth nursery of Berlin from the 1880s, a specimen of which survives in hedge form in Kew Gardens' Wakehurst Place collection in England. An U. montana atropurpurea supplied by Späth was planted in 1896 at the Dominion Arboretum, Ottawa, Canada,[6] while three specimens were supplied by Späth in 1902 to the Royal Botanic Garden Edinburgh, whose practice it was to distribute trees about the city.[23] Specimens of both U. campestris purpurea and U. montana purpurea stood in the Ryston Hall arboretum, Norfolk,[24] in the early 20th century.[25] The former was supplied by Späth and planted in 1914; the origin of the latter, planted in 1920, is unrecorded.[25]

The cultivar U. × hollandica 'Purpurascens' was "produced in quantity" by nurseries in Oudenbosch, the Netherlands.[11][26] It appears to have been rarer in cultivation in the UK; Wilkinson in his researches for Epitaph for the Elm (1978) had never seen a specimen. An U. campestris purpurea, 'Purple-leaved English Elm', of "compact upright growth" with "leaves a purple color in May and June", appeared in the 1902 catalogue of the Bobbink and Atkins nursery, Rutherford, New Jersey,[27] and an U. stricta purpurea, also called 'Purple-leaved English Elm', "a tree with erect branches and purplish-red leaves", in both Bobbink and Atkins' 1902 catalogue and Kelsey's 1904 catalogue, New York.[28] An elm obtained in 1922 from H. Kohankie & Son was listed by the Morton Arboretum, Illinois, as Ulmus procera 'Purpurea',[29] but without description. In 2007 the Swedish Biodiversity Centre's 'Programme for Diversity of Cultivated Plants' included 'Purpurascens' (mistakenly called Ulmus procera 'Purpurea' in Sweden[30]) in their plant conservation programme.[31]

Notable trees

'Purpurea', Hedvig Eleonora Church, Stockholm, 2014

Several trees still survive in Europe, the UK and Australia. A large specimen stands in the gardens of the Hedvig Eleonora Church, Östermalm, Stockholm, listed as U. procera 'Purpurea'.[32][33][34] In the UK probably the largest is in Warriston Cemetery, Edinburgh (middle level). Six of the seven mature specimens growing there were felled in the 1990s; the seventh, near the east gate, remains healthy (2018) (height 20 m, bole-girth 2.2 m; labelled 03159 CEM). Ignorance of this cultivar may have occasioned unnecessary felling: the tree's naturally upcurled, greyish foliage in late summer may be mistaken for foliage affected by Dutch elm disease. A vigorous sucker in the cemetery has now become an established tree. In Australia the Avenue of Honour at Wallan, Victoria, was planted solely with 'Purpurascens' in the early 1920s, most of which survive,[35] and the cultivar was also included in the Avenue of Honour in Ballarat in 1918.[36]

Synonymy

  • Ulmus montana (: glabra) var. atropurpurea: Elwes and Henry[7]
  • Ulmus montana (: glabra) 'Purpurea': Kew Garden list of names[10]
  • Ulmus 'Purpurea': Koch ; Bean;[10] National Elm Collection elm list[37]
  • Ulmus x hollandica 'Purpurascens': Fontaine, Dendroflora No.5 (1968)
  • ?Ulmus campestris (: minor) 'Purpurea': Kirchner
  • ?Ulmus procera 'Purpurea': Morton Arboretum Catalogue 2006.

Accessions

Europe

Australia

North America

Nurseries

Europe

  • Centrum voor Botanische Verrijking vzw, Kampenhout, Belgium (as Ulmus glabra 'Purpurea').[38]
  • Loenbaek Planteskole , Holstebro, Denmark
  • Propagation Nurseries Vermeerderingstuin Horst and Zeewolde, Netherlands

References

  1. ↑ Koch, K. Dendrologie; Bäume, Sträucher und Halbsträucher, welche in Mittel- und Nord- Europa im Freien kultivirt werden 2 (1), 416 (1872)
  2. 1 2 Wood, John Frederick (1852). "Coppiceana". The Midland Florist and Suburban Horticulturist. London. 6: 365.
  3. ↑ Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus". Arnoldia. Arnold Arboretum, Harvard University. 24 (6–8): 41–80. Retrieved 16 February 2017.
  4. 1 2 3 Katalog (PDF). 108. Berlin, Germany: L. Späth Baumschulenweg. 1902–1903. pp. 132–133.
  5. 1 2 Späth, Ludwig (1930). Späth-Buch, 1720-1930. Berlin: Self published. pp. 311–313, 351–352.
  6. 1 2 3 Catalogue of the trees and shrubs in the arboretum and botanic gardens at the central experimental farm (2nd ed.). 1899. p. 75.
  7. 1 2 Elwes, Henry John; Henry, Augustine (1913). The Trees of Great Britain & Ireland. 7. p. 1868.
  8. ↑ Petzold; Kirchner (1864). Arboretum Muscaviense. p. 558.
  9. ↑ Elwes, Henry John; Henry, Augustine (1913). The Trees of Great Britain & Ireland. 7. p. 1905.
  10. 1 2 3 4 Bean, W. J. (1988) Trees and shrubs hardy in Great Britain, 8th edition, Murray, London, p. 640
  11. 1 2 F. J., Fontaine (1968). "Ulmus". Dendroflora. 5: 37–55. Retrieved 30 August 2017.
  12. ↑ "Inglise jalakas ´Purpurea´" [Purple English Elm]. jarvselja.ee (in Estonian). Retrieved 2017-08-31.
  13. ↑ Photograph of newly emerged leaves of 'Purpurea' in Denmark, www.loenbaek.dk
  14. ↑ Emerging 'Purpurea' leaves photographed against sunlight, www.kuningas.ee
  15. ↑ Photograph of 'Purpurea' cuttings, www.kuningas.ee
  16. ↑ Spencer, Roger, ed., Horticultural Flora of South-Eastern Australia, Vol. 2 (Sydney, 1995), Ulmus, p. 111-112
  17. ↑ Brookes, Margaret, & Barley, Richard, Plants listed in nursery catalogues in Victoria, 1855-1889 (Ornamental Plant Collection Association, South Yarra, Victoria, 1992), p.303–304
  18. ↑ Spencer, R.; Hawker, J. & Lumley, P. (1991). Elms in Australia. Australia: Royal Botanic Gardens, Melbourne. ISBN 0-7241-9962-4.
  19. ↑ Sibbing, Nick. "Significant Elms of South-Eastern Australia". advancedtrees.com.au. Retrieved 2017-06-19.
  20. ↑ Spencer, Roger, ed., Horticultural Flora of South-Eastern Australia, Vol. 2 (Sydney, 1995), 111–112
  21. ↑ 'Purpurascens' in Fawkner Park, Melbourne: elsewhere.polydistortion.net
  22. ↑ Spencer, Roger, ed., Horticultural Flora of South-Eastern Australia, Vol. 2 (Sydney, 1995), p. 112
  23. ↑ Accessions book. Royal Botanic Garden Edinburgh. 1902. pp. 45, 47.
  24. ↑ rystonhall.co.uk/
  25. 1 2 Ryston Hall Arboretum catalogue. c. 1920. pp. 13–14.
  26. ↑ E. E. Kemp (Curator, Royal Botanic Garden Edinburgh 1950-71) in After the Elm, eds. Clouston & Stansfield, (London, 1979), p.35
  27. ↑ Bobbink and Atkins, Rutherford. N.J. 1902. p. 51.
  28. ↑ General catalogue, 1904 : choice hardy trees, shrubs, evergreens, roses, herbaceous plants, fruits, etc. New York: Frederick W. Kelsey. 1904. p. 18.
  29. ↑ Ulmus procera 'Purpurea': Morton Arboretum Catalogue, Accession no. 593–22
  30. ↑ Lagerstedt, Lars (2014). "Märkesträd i Sverige - 10 Almar" [Notable trees in Sweden - 10 Elms] (PDF). Lustgården. 94: 60, 71, 76. Retrieved 15 May 2018.
  31. ↑ Leaves and samarae of 'Purpurascens', 'Programme for Diversity of Cultivated Plants', Sweden, pom.info,
  32. ↑ www.tradgardsakademin.se
  33. ↑ Photograph of 'Purpurea', Hedvig Eleonora Church, Stockholm (to right of church)
  34. ↑ Aerial photograph of Hedvig Eleonora Church, the dark crown of 'Purpurea' visible near the east window
  35. ↑ Photographs of 'Purpurascens', Avenue of Honour, Wallan, Victoria: vhd.heritage.vic.gov.au
  36. ↑ ballarat.com Archived 2014-04-13 at the Wayback Machine.
  37. ↑ National Elm Collection list www.brighton-hove.gov.uk/index.cfm?request=c1108042
  38. ↑ Centrum voor Botanische Verrijking vzw: Voorraadlijst, accessdate: November 2, 2016
  • "Herbarium specimen - L.1581936". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled U. procera Salisb. var. stricta purpurea (Arnold Arboretum specimen, 1930)
  • "Herbarium specimen - L.1581933". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled U. procera Salisb. var. purpurea Rehder (Arnold Arboretum specimen, 1930)
  • "Herbarium specimen - L.1590639". Botany catalogues. Naturalis Biodiversity Center. [?]
  • Herbarium specimen of U. montana purpurea, science.udau.edu.ua
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