Jump to content

Ulmus laevis: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
mNo edit summary
No edit summary
Line 26: Line 26:
*''Ulmus simplicidens'' <small>E. Wolf</small>
*''Ulmus simplicidens'' <small>E. Wolf</small>
}}
}}
'''''Ulmus laevis''''' <small>Pall.</small>, the '''European White Elm''', '''Fluttering Elm, Spreading Elm''' and, in the [[USA]], '''Russian Elm''', is a large [[deciduous]] [[tree]] native to [[Europe]], from [[France]] northeast to southern [[Finland]], east as far as the [[Urals]], and southeast to [[Bulgaria]] and the [[Crimea]]; there is also a disjunct population in the [[Caucasus]]. Moreover, a small number of trees found in [[Spain]] is now considered a relict population rather than an introduction by man, and possibly the origin of the European population <ref name=Fuentes-Utrilla>Fuentes-Utrilla, P., Squirrell, J., Hollingsworth, P. M. & Gil, L. (2006). ''Ulmus laevis (Pallas) in the [[Iberian Peninsula]]. An introduced or relict tree species? New data from [[cpDNA]] analysis.'' Genetics Society, Ecological Genetics Group conference, University of Wales Aberystwyth 2006.</ref>.
'''''Ulmus laevis''''' <small>Pall.</small>, the '''European White Elm''', '''Fluttering Elm, Spreading Elm''' and, in the [[USA]], '''Russian Elm''', is a large [[deciduous]] [[tree]] native to [[Europe]], from [[France]] <ref>Photographs of ''U. laevis'' (''L'Orme lisse'') in France: in the Forêt du Romersberg, Moselle, [http://krapooarboricole.wordpress.com/category/arbres-coup-de-coeur/ormes/page/2/], and near Walbourg, Bas-Rhin,[http://krapooarboricole.wordpress.com/category/arbres-coup-de-coeur/ormes/page/3/] Archive Krapo arboricole</ref> northeast to southern [[Finland]], east as far as the [[Urals]], and southeast to [[Bulgaria]] and the [[Crimea]]; there is also a disjunct population in the [[Caucasus]]. Moreover, a small number of trees found in [[Spain]] is now considered a relict population rather than an introduction by man, and possibly the origin of the European population <ref name=Fuentes-Utrilla>Fuentes-Utrilla, P., Squirrell, J., Hollingsworth, P. M. & Gil, L. (2006). ''Ulmus laevis (Pallas) in the [[Iberian Peninsula]]. An introduced or relict tree species? New data from [[cpDNA]] analysis.'' Genetics Society, Ecological Genetics Group conference, University of Wales Aberystwyth 2006.</ref>.


Essentially endemic to alluvial forest, it is rarely encountered at elevations above 400 m <ref name=Girard>Girard, S. (2007). Dossier: L'orme: nouveaux espoirs? ''Forêt entreprise'' No. 175, Juillet 2007, Institut pour le developpement forestier, Paris.</ref>. Most commonly found along rivers such as the [[Volga]] and [[Danube]], it is one of very few elms tolerant of prolonged waterlogged, [[Hypoxia (environmental)|anoxic]] ground conditions. The White Elm is [[allogamous]] and is most closely related to the American Elm ''[[Ulmus americana|U. americana]]''.
Essentially endemic to alluvial forest, it is rarely encountered at elevations above 400 m <ref name=Girard>Girard, S. (2007). Dossier: L'orme: nouveaux espoirs? ''Forêt entreprise'' No. 175, Juillet 2007, Institut pour le developpement forestier, Paris.</ref>. Most commonly found along rivers such as the [[Volga]] and [[Danube]], it is one of very few elms tolerant of prolonged waterlogged, [[Hypoxia (environmental)|anoxic]] ground conditions. The White Elm is [[allogamous]] and is most closely related to the American Elm ''[[Ulmus americana|U. americana]]''.


==Description==
==Description==
The tree is similar in stature to the [[Wych Elm]], if rather less symmetric, with a looser branch structure and less neatly rounded crown. It typically reaches a height and breadth of > 30 m, with a trunk < 2 m [[diameter at breast height|d.b.h]]. The extensive shallow root system ultimately forms distinctive high buttresses around the base of the trunk. The [[leaf|leaves]] are [[deciduous]], alternate, simple [[leaf shape|ovate]] with a markedly lop-sided base, < 10 cm long and < 7 cm broad, comparatively thin, often almost papery in texture and very translucent, smooth above with a downy underside. ''U. laevis'' sheds its leaves earlier in the autumn than other species of European elm. The [[apetalous]] wind-pollinated [[flower]]s appear before the leaves in early spring, produced in clusters of 15-30; they are 3-4 mm across on 20 mm long stems. In England, trees grown from seed flower in March, commencing at ages of between 7 and 12 years.
The tree is similar in stature to the [[Wych Elm]], if rather less symmetric, with a looser branch structure and less neatly rounded crown. It typically reaches a height and breadth of > 30 m, with a trunk < 2 m [[diameter at breast height|d.b.h]]. The extensive shallow root system ultimately forms distinctive high buttresses around the base of the trunk. The [[leaf|leaves]] are [[deciduous]], alternate, simple [[leaf shape|ovate]] with a markedly lop-sided base, < 10 cm long and < 7 cm broad, comparatively thin, often almost papery in texture and very translucent, smooth above with a downy underside. The [[apetalous]] wind-pollinated [[flower]]s appear before the leaves in early spring, produced in clusters of 15-30; they are 3-4 mm across on 20 mm long stems. In England, trees grown from seed flower in March, commencing at ages of between 7 and 12 years.
The [[fruit]] is a winged [[Samara (fruit)|samara]] < 15 mm long by 10 mm broad with a [[ciliate]] margin, the single round 5 mm [[seed]] maturing in late spring.
The [[fruit]] is a winged [[Samara (fruit)|samara]] < 15 mm long by 10 mm broad with a [[ciliate]] margin, the single round 5 mm [[seed]] maturing in late spring. ''U. laevis'' sheds its leaves earlier in the autumn than other species of European elm.
The tree is most reliably distinguished from other European elms by the long flower stems, and is most closely related to the [[American Elm]] ''U. americana'', from which it differs mainly in the irregular crown shape and frequent small sprout stems on the trunk and branches. Its irregular crown and frequent sprout-stems give ''U.laevis'' a densely-branched winter silhouette - a useful diagnostic feature at this season.<ref name=Bean>Bean, W. J. (1981). ''Trees and shrubs hardy in Great Britain'', 7th edition. Murray, London.</ref> <ref name=Elwes>Elwes, H. J. & Henry, A. (1913). ''The Trees of Great Britain & Ireland''. Vol. VII. pp 1848-1929. Private publication. [http://fax.libs.uga.edu/QK488xE4/7tgbi/]</ref> <ref name=White>White, J. & More D. (2003). ''The Trees of Britain & Northern Europe'', Cassell's, London. </ref>
The tree is most reliably distinguished from other European elms by the long flower stems, and is most closely related to the [[American Elm]] ''U. americana'', from which it differs mainly in the irregular crown shape and frequent small sprout stems on the trunk and branches. Its irregular crown and frequent sprout-stems give ''U.laevis'' a densely-branched winter silhouette - a useful diagnostic feature at this season.<ref name=Bean>Bean, W. J. (1981). ''Trees and shrubs hardy in Great Britain'', 7th edition. Murray, London.</ref> <ref name=Elwes>Elwes, H. J. & Henry, A. (1913). ''The Trees of Great Britain & Ireland''. Vol. VII. pp 1848-1929. Private publication. [http://fax.libs.uga.edu/QK488xE4/7tgbi/]</ref> <ref name=White>White, J. & More D. (2003). ''The Trees of Britain & Northern Europe'', Cassell's, London. </ref>


Revision as of 14:09, 10 December 2010

Ulmus laevis
European White Elm in winter
Scientific classification
Kingdom:
Plantae
Division:
Magnoliophyta
Class:
Magnoliopsida
Order:
Rosales
Family:
Ulmaceae
Genus:
Ulmus
Species:
U. laevis
Binomial name
Ulmus laevis
Synonyms
  • Ulmus acuta Dumrt.
  • Ulmus ciliata Ehrh.
  • Ulmus effusa Willd., Loudon, Willkomm, Fliche
  • Ulmus laevis var. celtidea Rogowicz
  • Ulmus laevis var. simplicidens (E. Wolf) Grudz.
  • Ulmus octandra Schkuhr
  • Ulmus pedunculata Foug.
  • Ulmus petropolitana Gand.
  • Ulmus racemosa (not Thomas), Borkh.
  • Ulmus reticulata Dumrt.
  • Ulmus simplicidens E. Wolf

Ulmus laevis Pall., the European White Elm, Fluttering Elm, Spreading Elm and, in the USA, Russian Elm, is a large deciduous tree native to Europe, from France [1] northeast to southern Finland, east as far as the Urals, and southeast to Bulgaria and the Crimea; there is also a disjunct population in the Caucasus. Moreover, a small number of trees found in Spain is now considered a relict population rather than an introduction by man, and possibly the origin of the European population [2].

Essentially endemic to alluvial forest, it is rarely encountered at elevations above 400 m [3]. Most commonly found along rivers such as the Volga and Danube, it is one of very few elms tolerant of prolonged waterlogged, anoxic ground conditions. The White Elm is allogamous and is most closely related to the American Elm U. americana.

Description

The tree is similar in stature to the Wych Elm, if rather less symmetric, with a looser branch structure and less neatly rounded crown. It typically reaches a height and breadth of > 30 m, with a trunk < 2 m d.b.h. The extensive shallow root system ultimately forms distinctive high buttresses around the base of the trunk. The leaves are deciduous, alternate, simple ovate with a markedly lop-sided base, < 10 cm long and < 7 cm broad, comparatively thin, often almost papery in texture and very translucent, smooth above with a downy underside. The apetalous wind-pollinated flowers appear before the leaves in early spring, produced in clusters of 15-30; they are 3-4 mm across on 20 mm long stems. In England, trees grown from seed flower in March, commencing at ages of between 7 and 12 years. The fruit is a winged samara < 15 mm long by 10 mm broad with a ciliate margin, the single round 5 mm seed maturing in late spring. U. laevis sheds its leaves earlier in the autumn than other species of European elm. The tree is most reliably distinguished from other European elms by the long flower stems, and is most closely related to the American Elm U. americana, from which it differs mainly in the irregular crown shape and frequent small sprout stems on the trunk and branches. Its irregular crown and frequent sprout-stems give U.laevis a densely-branched winter silhouette - a useful diagnostic feature at this season.[4] [5] [6]

U. laevis suckers from roots, but not stools.

  • U. laevis flowers; note the long stems
    U. laevis flowers; note the long stems
  • U. laevis seed; note ciliate margins
    U. laevis seed; note ciliate margins
  • U. laevis foliage; autumn colour
    U. laevis foliage; autumn colour

Pests and diseases

Like other European elms, natural populations of the European White Elm have little innate resistance to Dutch elm disease, although research by Cemagref has isolated clones able to survive inoculation with the causal fungus, initially losing < 70 % of their foliage, but regenerating strongly the following year. Moreover, the tree is not favoured by the vector bark beetles, which colonize it only when there are no other elm alternatives available [7], an uncommon situation in western Europe. Research in Spain [8] has indicated that it is the presence of a triterpene, alnulin, that renders the tree bark unattractive to the beetles. Ergo: the tree's decline in western Europe is chiefly owing to woodland clearance in river valleys, not disease.

The species has a slight to moderate susceptibility to Elm Yellows, but a very low susceptibility to the elm leaf beetle Xanthogaleruca luteola.[9]

Cultivation

Although ideally suited to wet ground conditions, the tree can still grow, albeit more slowly, on drier sites including chalk downland. However, one overriding factor in choosing a site is Exposure. White Elm is comparatively weak-wooded, much more so than Field Elm Ulmus minor, and thus an inappropriate choice for windy locations. In trials in southern England by Butterfly Conservation, young trees of < 5 m height were badly damaged by gusts of 40 knots (75 km/h) in midsummer.

The species was never widely introduced to the USA, but is represented at several arboreta. In the Far East, the tree has been planted in Xinjiang province and elsewhere in Northern China; planting in Tongliao City is known to have been particularly successful. White Elm is also known to have been introduced to Australia [10]. In recent years, the tree has enjoyed a small renaissance in England. A popular larval host plant of the White-letter Hairstreak Satyrium w-album butterfly across Europe, the elm is now being planted by Butterfly Conservation and other groups to restore local populations decimated by the effects of Dutch elm disease on native or archaeophytic elms [11]. The Cheshire Wildlife Trust, for example, is planting 1,000 White Elms on its reserves in the former Vale Royal district of the county.

Uses

The timber of the White Elm is of poor quality and thus of little use to man, not even as firewood. Its density is significantly lower than that of other European elms.

Propagation

Usually easy to grow from seed sown to a depth of 6 mm in ordinary compost and kept well-watered. However, as seed viability can vary greatly from year to year, softwood cuttings taken in June may be a more reliable method. The cuttings strike very quickly, well within a fortnight, rapidly producing a dense matrix of roots.

Notable trees

European White Elm, Alfriston, East Sussex, UK (2006)

The two largest known trees in Europe are at Gülitz in Germany (3.1 m d.b.h.), and Komorów in Poland (2.96 m d.b.h.). The UK Champion is at Ferry Farm, Harewood, Cornwall (27 m high, 1.8 m d.b.h.). Other examples in the UK are few and far between, but sometimes of great age. Several survive amid diseased native elm near Torpoint in Cornwall [7]; others can be found in Edinburgh (The Meadows area; Powderhall Road); London (Riverside Walk, near Royal Botanic Gardens, Kew, and at Peckham and Tooting); Chelmsford (beside the Chelmer at the Rivermead Campus) [2009]; Brighton & Hove; and near St. Albans. In the USA, a reputedly magnificent tree grows in Portland, Oregon, but its dimensions and age are not known.

Subspecies and varieties

The species is not divided into subspecies or varieties. A variety celtidea (occasionally treated as a species) from what is now the Ukraine was reported by Rogowicz in the middle of the 19th century, but no examples are known to survive.

Forms

In Russia several decorative forms are recognized: f. aureovariegata, f. argentovariegata, f. rubra, and f. tiliifolia.

Cultivars

Compared with the other European species U. glabra and U. minor, U. laevis has received scant horticultural attention, there being only five recorded cultivars, none of which are known to remain in cultivation, with the possible exception of 'Colorans' and 'Pendula': Aureovariegata, Colorans, Ornata, Pendula, Punctata, Urticifolia.

Hybrid cultivars

U. laevis does not hybridize naturally, in common with the American Elm U. americana to which it is closely related. The few reported instances of artificial hybridization in the 19th century are now regarded with suspicion.

Accessions

North America
Europe

Nurseries

North America

None known

Europe

Seed suppliers

References

  1. ^ Photographs of U. laevis (L'Orme lisse) in France: in the Forêt du Romersberg, Moselle, [1], and near Walbourg, Bas-Rhin,[2] Archive Krapo arboricole
  2. ^ Fuentes-Utrilla, P., Squirrell, J., Hollingsworth, P. M. & Gil, L. (2006). Ulmus laevis (Pallas) in the Iberian Peninsula. An introduced or relict tree species? New data from cpDNA analysis. Genetics Society, Ecological Genetics Group conference, University of Wales Aberystwyth 2006.
  3. ^ Girard, S. (2007). Dossier: L'orme: nouveaux espoirs? Forêt entreprise No. 175, Juillet 2007, Institut pour le developpement forestier, Paris.
  4. ^ Bean, W. J. (1981). Trees and shrubs hardy in Great Britain, 7th edition. Murray, London.
  5. ^ Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland. Vol. VII. pp 1848-1929. Private publication. [3]
  6. ^ White, J. & More D. (2003). The Trees of Britain & Northern Europe, Cassell's, London.
  7. ^ Collin, E., Bilger, I., Eriksson, G., & Turok, J. (2000). The conservation of elm genetic resources in Europe. In Dunn, C. P. (Ed.) (2000). The elms: breeding, conservation & disease management. Kluwer Academic Publishers, Boston.
  8. ^ Martín-Benito D., Concepción García-Vallejo M., Alberto Pajares J., López D. 2005. Triterpenes in elms in Spain. Can. J. For. Res. 35: 199–205 (2005). [4]
  9. ^ Mittempergher, L. & Santini, A. (2004). The History of Elm Breeding. Invest. Agrar.: Sist Recur For. 2004 13 (1), 161-177.
  10. ^ Spencer, R., Hawker, J. and Lumley, P. (1991). Elms in Australia, Royal Botanic Gardens, Melbourne, Australia. ISBN 0-7241-9962-4
  11. ^ Brookes, A. H. (2006). An evaluation of disease-resistant hybrid and exotic elms as larval host plants for the White-letter Hairstreak Satyrium w-album, Part 1. [5]. Butterfly Conservation. Lulworth, UK.
  12. ^ Ulmus laevis at Morton Arboretum, [6]
Retrieved from "https://en.wikipedia.org/w/index.php?title=Ulmus_laevis&oldid=401618099"