Wych Elm
From Wikipedia, the free encyclopedia
 |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 Wych Elm leaves and seeds
|
||||||||||||||
|
|
||||||||||||||
| Scientific classification | ||||||||||||||
|
||||||||||||||
|
|
||||||||||||||
| Ulmus glabra Huds. |
The Wych Elm Ulmus glabra Huds., or Scots Elm, is a large deciduous tree native to Europe, Asia Minor, and the Caucasus. Essentially a montane species, the tree occurs as far north as latitude 67°N at Beiarn in Norway. In the British Isles, it was by far the most common elm in the north and west of the region. Closely related species such as Bergmann's Elm U. bergmanniana and Manchurian Elm U. laciniata, native to north-east Asia, were once sometimes included in Ulmus glabra. Another close relative is the Himalayan Elm U. wallichiana.
The tree sometimes reaches heights of 40 m, typically with a broad crown supported by a short bole < 2 m in diameter. It is notable for its very tough, supple young shoots. The leaves are deciduous, alternate, simple ovate or obovate with a lop-sided base, 6-17 cm long and 3-12 cm broad; the upper surface is rough. Leaves on vigorous shoots are sometimes three-lobed near the apex. The flowers appear before the leaves in early spring, produced in clusters of 10-20 together; they are 4 mm across on 1cm long stems and, being wind-pollinated, have no petals. The fruit is a winged samara 20 mm long and 15 mm broad, with a single round 6 mm seed, maturing in late spring.
Contents |
[edit] Subspecies
Some botanists divide the species into two subspecies:
- Ulmus glabra subsp. glabra. In the south of the species' range. Leaves broad; trees often with a short, forked trunk and a low, broad crown.
- Ulmus glabra subsp. montana (Stokes) Lindqvist. In the north of the species' range (northern Britain, Scandinavia). Leaves narrower; trees commonly with a long single trunk and a tall, narrow crown.
However, there is much overlap between populations in these characters and the distinction may be owing to environmental influence, rather than genetic variation; the subspecies are not accepted by Flora Europaea.
[edit] Dutch Elm Disease
The species is highly susceptible to Dutch elm disease. As it does not sucker extensively from the roots, and any seedlings are often consumed by uncontrolled deer populations, regrowth is very restricted, limited to sprouts from the stumps of young trees. The resultant decline has been extreme and the Wych Elm is now uncommon over much of its former range. In 1998, over 700 healthy, mature trees were discovered on the upper slopes of Mount Simonka in Slovakia, but it is now believed they had survived courtesy of their isolation from disease-carrying beetles rather than any innate resistance (50 clones of these trees were presented to HRH The Prince of Wales for planting at his Highgrove estate, and at Clapham, Yorkshire) [1]. Indeed, DNA analysis by Cemagref in France has determined that genetic diversity within the species is very limited, making the chances of finding a resistant tree rather remote.
[edit] Arboreta etc specimens
[edit] North America
- Arnold Arboretum, acc. no. 391-2001, wild collected in Georgia (former USSR?)
- Bartlett Tree Experts, acc. nos. 1505, 5103, origin undisclosed.
- Morton Arboretum, Acc. nos. 591-54, 255-81, and by its synonym U. sukaczevii Acc. nos. 949-73, 181-76
[edit] Europe
Too numerous to list
[edit] Nurseries
[edit] North America
None known
[edit] Europe
Widely available
[edit] Australasia
- Established Trees Transplanters Pty. Ltd., Wandin, Victoria, Australia, [2]. No details given.
[edit] Cultivars
A number of cultivars of significant horticultural merit have been raised, although many are now probably lost to cultivation:
- Albo-Variegata, Atropurpurea, Australis, Camperdownii (Camperdown Elm), Cebennensis (Cevennes Elm), Cornuta, Corylifolia, Corylifolia Purpurea, Crispa, Crispa Aurea, Dovaei, Escaillard, Exoniensis (Exeter Elm), Fastigiata macrophylla, Fastigiata stricta, Fastigiata variegata, Firma, Flava, Gittisham, Holgeri, Horizontalis (Weeping Wych Elm), Insularis, Latifolia Aurea, Latifolia Aureo-Variegata, Latifolia Nigricans, Luteo Variegata, Lutescens (Golden Wych Elm), Macrophylla, Maculata, Minor, Monstrosa, Nana (Dwarf Wych Elm), Nigra (Black Irish Elm), Oblongata, Pendula Macrophylla, Pendula Variegata, Purpurea, Ramulosa, Rubra, Rugosa, Spectabilis, Tiliaefolia, Tomentosa.
[edit] Hybrids and hybrid cultivars
Wych Elm has naturally hybridized with U. minor across much of Europe, their ranges widely overlapping. The hybrid is loosely known as 'Dutch Elm' Ulmus × hollandica; several cultivars of which (notably Vegeta, the Chichester Elm or Huntingdon Elm) have a moderate resistance to Dutch elm disease. The tree has also featured strongly in artificial hybridization experiments in Europe, notably at Wageningen in the Netherlands, and a number of hybrid cultivars have been commercially released since 1960. The earlier trees were raised in response to the initial Dutch elm disease pandemic that afflicted Europe after the First World War, and were to prove vulnerable to the much more virulent strain of the disease that arrived in the late 1960s. However, further research eventually produced several trees immune to disease that were released after 1989.
[edit] Natural hybrids
[edit] Hybrid cultivars
- Alba, Angustifolia, Arno, Belgica (Belgian Elm), Cinerea, Clusius, Columella, Commelin, Dampieri, Dauvessei, Daveyi (Davey Elm), Den Haag, Dodoens, Dumont, Eleganto-Variegata, Etrusca, Fjerrestad, Fulva, Gaujardii, Groeneveld, Haarlemensis, Hillieri, Homestead, Jacqueline Hillier, Lobel, Major (Dutch Elm), Macrophylla Aurea, Microphylla, Modiolina, Muscaviensis, Nanguen (LUTECE™), Pioneer, Plinio, Regal, San Zanobi, Serpentina, Smithii (Downton Elm), Stavast, Superba, Tricolor, Urban, Vegeta (Huntingdon Elm), Vegeta (Chichester Elm), Virens (Kidbrook Elm), Viscosa, Warnoux (VADA™), Wredei (Golden Elm), Ypreau.
[edit] Etymology
The word wych has its origins in Middle English wiche, from the Old English wice, meaning pliant or supple, and which also gives us wicker and weak. Owing to its former abundance in Scotland, it was occasionally known as the 'Scotch (sic) Elm'; the name Loch Lomond a corruption of the Gaelic Lac Leaman, or 'Lake of the Elms'.
[edit] Synonymy
- Ulmus campestris L., Mill., Wilkomm
- Ulmus elliptica Koch
- Ulmus excelsa Borkh.
- Ulmus montana Stokes, Smith, Loudon, Mathieu, With.
- Ulmus nuda Ehrh.
- Ulmus podolica (Wilcz.) Klok.
- Ulmus popovii Giga.
- Ulmus scabra Mill., C. K. Schneid., Ley, Ascherson & Graebner
- Ulmus suberosa Michx.
- Ulmus sukaczevii Andronov
[edit] References
- Flora Europaea: Ulmus glabra
- Bean, W. J. (1981). Trees and shrubs hardy in Great Britain, 7th edition. Murray, London.
- Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland. Vol. VII. pp 1848-1929. Private publication, Edinburgh. [3]
- Green, P. S. (1964). Registration of cultivar names in Ulmus. Arnoldia. Vol. 24. Arnold Arboretum, Harvard University. [4]
- Heybroek, H. (1983). The Dutch elm breeding program. In Sticklen & Sherald (Eds). Dutch elm disease research (Ch. 3). Springer Verlag, New York.
- Richens, R. H. (1983). Elm. Cambridge University Press.
- White, J. & More, D. (2003). Trees of Britain and Northern Europe. Cassell's, London.
[edit] External links
- http://northernontarioflora.ca/chklst.cfm?speciesid=1005114 Synonymy list.
