ULMUS PUMILA

'''Ulmus pumila''' L., the 'Siberian Elm', is native to Turkestan, eastern Siberia, Mongolia, Tibet, northern China, India (northern Kashmir) and Korea. It is also known as the 'Asiatic Elm, Dwarf Elm' and (erroneously) 'Chinese Elm'. The tree has also been widely cultivated throughout Asia, North America and, to a lesser extent, southern Europe. It is usually a small to medium-sized, often bushy, tree growing to 10 - 20 m tall, with a trunk up to 80 cm d.b.h. (diameter at breast height). The leaves are deciduous in cold areas, but semi-evergreen in warmer climates, < 7 cm long and < 3 cm broad, with an oblique base and a coarsely serrated margin, changing from dark green to yellow in autumn. The wind-dispersed fruit develops in a flat, oval membranous wing (:samara) 1 - 1.5 cm long and notched at the outer end.
The variety ''arborea'' from Turkestan is more handsome, growing to 30 m with a broad, rounded crown.

Contents

Ecology

Invasiveness

Cultivation and uses

Cultivars

Hybrid cultivars

Arboreta etc. accessions

North America

Europe

Australasia

Nurseries

North America

Europe

Australasia

Seed suppliers

References

External links

Ecology

The Siberian elm has a high sunlight requirement and is not shade-tolerant. With adequate light it exhibits rapid growth. It is also fairly intolerant of wet ground conditions, growing better on well-drained soils. While it is very resistant to drought and severe cold, and able to grow on poor soils, its habit of flowering early in spring and retaining its foliage until late in the fall renders it vulnerable to frost damage. Moreover, like many other elms in North America it is highly susceptible to damage from many insects and parasites, including the elm leaf beetle, powdery mildew, cankers, aphids, and leaf spot.

Invasiveness

In North America it has become an invasive species from Utah east to Kansas and north to Ontario. It is found in abundance along railroads and in abandoned lots and on disturbed ground. The gravel along railroad beds provides ideal conditions for its growth: well-drained, nutrient poor soil, and high light conditions, and these beds provide corridors which facilitate its spread. Owing to its high sunlight requirements, it seldom invades mature forests, and is primarily a problem in cities and open areas.
The tree was introduced into Spain in the 16th century, and later Italy, where it has naturally hybridized with the Field Elm ''U. minor''.

Cultivation and uses

''U. pumila'' was successfully planted in great numbers in shelter belts acoss the prairies in the aftermath of the Dustbowl disasters, owing to its rapid growth and tolerance for drought and cold, but it later proved susceptible to various maladies. Attempts to find a more suitable cultivar were initiated in 1997 by the Plant Materials Center of the USDA, which established experimental plantations at Akron, Colorado and Sidney, Nebraska. The study, no. 201041K, will conclude in 2020. In Italy it was widely used in viniculture, notably in the Po valley, to support vines until the 1950s, when the demands of mechanization made it unsuitable.
As an ornamental it is a very poor tree, tending to be short-lived, with brittle wood and poor crown shape, but has nevertheless enjoyed some popularity owing to its rapid growth and provision of shade. The tree has been described as "one of, if not ''the'', world's worst trees...a poor ornamental that does not deserve to be planted anywhere" (Dirr, 1975).
In the UK, its popularity has been almost exclusively as a bonsai subject, and mature trees are largely restricted to arboreta.

Cultivars

Valued for its high resistance to Dutch elm disease, over a dozen selections have been made to produce hardy ornamental cultivars, although several many no longer be in cultivation:

★ Ansaloni, Aurescens, Chinkota, Dropmore, Green King, Hansen, Harbin, Manchu, Mr. Buzz, Park Royal, Pendula, Pyramidalis Fiorei, Variegata

Hybrid cultivars

The species has been widely hybridized in the USA and Italy to create robust trees of more native appearance with high levels of resistance to Dutch elm disease:

★ Arno, Cathedral, Commendation™, Coolshade, Fiorente, Homestead, Lincoln, New Horizon, Plinio, Regal, Rosehill, San Zanobi, Urban, Vanguard™, Willis.

Arboreta etc. accessions

North America

★ Arnold Arboretum, acc. nos. 17923, 638-79, 673-87.

★ Denver Botanic Gardens, acc. no. 900534.

★ Holden Arboretum, acc. nos. 99-868, 72-218

★ Longwood Gardens, acc. no. 1962-0512.

★ Morton Arboretum, acc. nos. 542-49, 325-70, 53-74, 172-U.

Europe

★ Arboretum de La Petite Loiterie [1], Monthodon, France. No details available

★ Brighton & Hove City Council, UK, NCCPG Elm Collection[2].

★ Hortus Botanicus Nationalis, Salaspils, Latvia acc. nos. 18162,3,4.

★ Royal Botanic Garden, Wakehurst Place, UK, acc. no. 2000-4449.

★ Copenhagen University, Botanic Garden, one specimen, no details available.

Australasia

★ Alma Park, St Kilda, Victoria, Australia, one specimen, listed on the National Trust of Victoria's Significant Tree Register.

Nurseries

North America

★ Cumberland Mountain Nursery, Beersheba Springs, TN. [3]

★ Mingo Nursery, Winchester, TN. [4]

Europe

★ Beeches Nursery, Saffron Walden, UK, [5].

★ Jardineria Sils [6], Sils, Girona, Spain.

★ Norfields, Usk, Monmouthshire, UK, [7].

★ UmbraFlor [8], Spello, Italy

★ Weasdale Nursery, Kirkby Stephen, UK, [9].

Australasia

★ Established Tree Planters Pty. Ltd., Wandin, Victoria, Australia. [10]

Seed suppliers

★ B and T World Seeds, Paguignan, 34210 Aigues-Vives, France [11]

★ Chiltern Seeds, Bortree Stile, Ulverston, Cumbria, LA12 7PB, England [12]

★ Lawyer Nursery, Montana Highway, 6625 West Plains, MT., USA [13]

★ Sandeman Seeds, 7 Route de Burosse, 64350 Lalongue, France [14]

References

★ Dirr, M. (1975). ''Manual of Woody Landscape Plants''. Stipes Publishing LLC. Champaign, Illinois.

★ Elwes, H. J. & Henry, A. (1913). ''The Trees of Great Britain & Ireland''. Vol. VII. pp 1848-1929. Private publication. [15]

★ Fu, L., Xin, Y. & Whittemore, A. (2002). Ulmaceae, in Wu, Z. & Raven, P. (eds) ''Flora of China'', Vol. 5 (Ulmaceae through Basellaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, USA. [16]

★ Huxley, A. (1992). ''The New RHS Dictionary of Gardening''. Macmillan.

★ National Audubon Society (2002). ''Field Guide to North American Trees'', Western Region, p. 419-420.

★ Rushforth, K. (1999). ''Trees''. Collins.

External links

★ [17] See pages 42,43. Evaluation of the Siberian Elm (Ulmus pumila), USDA.

★ Siberian Elm, ''Ulmus pumila'' Diagnostic photographs; specimen at Morton Arboretum

★ USDA Plant Guide: ''Ulmus pumila''

★ Notes on Elm in the Korqin Sandy Lands, Northeast China

★ ZipcodeZoo: ''Ulmus pumila''