Elm bark

''Ulmus rubra'', the slippery elm, is a species of elm native to eastern North America.
Other common names include red elm, gray elm, soft elm, moose elm, and Indian elm.

Description

''Ulmus rubra'' is a medium-sized deciduous tree with a spreading head of branches,Hillier & Sons. (1990). ''Hillier's Manual of Trees & Shrubs, 5th ed.''. David & Charles, Newton Abbot, UK commonly growing to , very occasionally over in height. Its heartwood is reddish-brown. The broad oblong to obovate leaves are long, rough above but velvety below, with coarse double-serrate margins, acuminate apices and oblique bases; the petioles are long.Bean, W. J. (1970). ''Trees & Shrubs Hardy in the British Isles'', 8th ed., p. 656. (2nd impression 1976) John Murray, London. The leaves are often tinged red on emergence, turning dark green by summer and a dull yellow in autumn.Missouri Botanical Garden, ''Ulmus rubra''
/ref> The perfect, apetalous, wind-pollinated flowers are produced before the leaves in early spring, usually in tight, short-stalked, clusters of 10–20. The reddish-brown fruit is an oval winged samara, orbicular to obovate, slightly notched at the top, long, the single, central seed coated with red-brown hairs, naked elsewhere.

File:Ulmus rubra flower buds.jpg, Downy leaf bud and flower buds of ''U. rubra''
File:Ulmus rubra flowers.jpg, ''U. rubra'' flowers
File:Ulmus rubra seeds.jpg, ''U. rubra'' fruit
File:Ulmus rubra leaf.jpg, Asymmetrical leaf of ''Ulmus rubra''
File:Ulmus rubra 8zz.jpg, Mature trunk bark
File:Photograph of Slippery Elm - NARA - 2127439.jpg, Slippery elm, Chippewa National Forest, Minnesota, 1923
File:Bulletin (Pennsylvania Department of Forestry), no. 11 (1901) (20313694880).jpg, Downy leaf-buds and seed area of samarae
File:Old Indian Elm at Maumee, Ohio - DPLA - 94c3734b1484eca5f274564b8202127a (page 1) (cropped).jpg, "Old Indian Elm at Maumee, O"

Similar species

The species superficially resembles American elm (''Ulmus americana''), but is more closely related to the European wych elm (''U. glabra''), which has a very similar flower structure, though lacks the pubescence over the seed.Elwes, H. J. & Henry, A. (1913).
The Trees of Great Britain & Ireland
'. Vol. VII. 1862-4 (as ''U. fulva''). Republished 2004 Cambridge University Press, ''U. rubra'' is chiefly distinguished from American elm by its downy twigs, chestnut brown or reddish hairy buds, and slimy red inner bark.

Taxonomy

The tree was first named as part of ''Ulmus americana'' in 1753, but identified as a separate species, ''U. rubra'', in 1793 by Pennsylvania botanist Gotthilf Muhlenberg. The slightly later name ''U. fulva'', published by French botanist André Michaux in 1803,Michaux, A. (1803). ''Flora Boreali-Americana'' ("The Flora of North America") is still widely used in information related to dietary supplements and alternative medicine.

Etymology

The specific epithet ''rubra'' (red) alludes to the tree's reddish wood, whilst the common name 'slippery elm' alludes to the mucilaginous inner bark.

The reddish-brown heartwood lends the tree the common name 'red elm'.

Distribution and habitat

The species is native to eastern North America, ranging from southeast North Dakota, east to Maine and southern Quebec, south to northernmost Florida, and west to eastern Texas, where it thrives in moist uplands, although it will also grow in dry, intermediate soils.

Ecology

Pests and diseases

The tree is reputedly less susceptible to Dutch elm disease than other species of American elms, but is severely damaged by the elm leaf beetle (''Xanthogaleruca luteola'').

File:Photograph of Red Elm Trees Browsed by Horses in Marshall, Illinois - NARA - 2129548.jpg, Red elm bark browsed by horses, Marshall, Illinois

Hybrids

In the central United States, native ''U. rubra'' hybridizes in the wild with the Siberian elm (''U. pumila''),Elowsky, C. G., Jordon-Thaden, I. E., & Kaul, R. B. (2013). A morphological analysis of a hybrid swarm of native Ulmus rubra and introduced U. pumila (Ulmaceae) in southern Nebraska. ''Phytoneuron'' 2013–44: 1–23. . which was introduced in the early 20th century and has spread widely since, prompting conservation concerns for the genetic integrity of the former species.

Cultivation

The species has seldom been planted for ornament in its native country. It occasionally appeared in early 20th-century US nursery catalogues. Introduced to Europe and Australasia, it has never thrived in the UK; Elwes & Henry knew of not one good specimen, and the last tree planted at Kew attained a height of only in 60 years. Specimens supplied by the Späth nursery to the Royal Botanic Garden Edinburgh in 1902 as ''U. fulva'' may survive in Edinburgh as it was the practice of the Garden to distribute trees about the city (''vide'' Wentworth Elm). A specimen at RBGE was felled c.1990. The current list of Living Accessions held in the Garden ''per se'' does not list the plant. Several mature trees survive in Brighton (see Accessions). The tree was propagated and marketed in the UK by the Hillier & Sons nursery, Winchester, Hampshire, from 1945, with 20 sold in the period 1970 to 1976, when production ceased.Hillier & Sons (1977). ''Catalogue of Trees & Shrubs''. Hillier, Ampfield, UK.Hillier & Sons ''Sales inventory 1962 to 1977'' (unpublished).

''U. rubra'' was introduced to Europe in 1830.

There are no known cultivars, though Meehan misnamed ''Ulmus americana'' 'Beebe's Weeping' as ''U. fulva pendula'' (1889) and Späth misnamed ''Ulmus americana'' 'Pendula' ''U. fulva'' (Michx.) ''pendula'' Hort. (1890). The hybrid ''U. rubra'' × ''U. pumila'' cultivar 'Lincoln' is sometimes erroneously listed as ''U. rubra'' 'Lincoln'.

Hybrid cultivars

''U. rubra'' had limited success as a hybrid parent in the 1960s, resulting in the cultivars 'Coolshade', 'Fremont', 'Improved Coolshade', 'Lincoln', 'Rosehill', and probably 'Willis'. In later years, it was also used in the Wisconsin elm breeding program to produce 'Repura' and 'Revera' although neither is known to have been released to commerce. In Germany, the tree formed part of a complex hybrid raised by the Eisele nursery in Darmstadt, provisionally named 'Eisele H1'; patent pending (2020).

Uses

Food

The mucilaginous inner bark of the tree is edible raw or boiled, and was eaten by Native Americans. The bark can also be used to make tea.

Medicinal

The species has various traditional medicinal uses. The inner bark has long been used as a demulcent, and is still produced commercially for this purpose in the United States with approval for sale as an over-the-counter demulcent by the US Food and Drug Administration. Sometimes the leaves are dried and ground into a powder, then made into a tea.

Timber

The timber is not of much importance commercially, and is not found anywhere in great quantity. Macoun considered it more durable than that of the other elms,Macoun, J. M. (1900). ''The Forest Wealth of Canada'', p. 24. Canadian Commission for the Paris International Exhibition 1900. and better suited for railway ties, fence-posts, and rails, while Pinchot recommended planting it in the Mississippi valley, as it grows fast in youth, and could be utilized for fence-posts when quite young, since the sapwood, if thoroughly dried, is quite as durable as the heartwood.Pinchot, G. (1907). ''U S Forest Circular'', no.85. The wood is also used for the hubs of wagon wheels, as it is very shock resistant owing to the interlocking grain. The wood, as 'red elm', is sometimes used to make bows for archery. The yoke of the Liberty Bell, a symbol of the independence of the United States, was made from slippery elm.

Baseball

Though now outmoded, slippery elm tablets were chewed by spitball pitchers to enhance the effectiveness of the saliva applied to make the pitched baseball curve. Gaylord Perry wrote about how he used slippery elm tablets in his 1974 autobiography, '' Me and the Spitter''.

Miscellaneous

The tree's fibrous inner bark produces a strong and durable fiber that can be spun into thread, twine, or rope useful for bowstrings, ropes, jewellery, clothing, snowshoe bindings, woven mats, and even some musical instruments. Once cured, the wood is also excellent for starting fires with the bow-drill method, as it grinds into a very fine flammable powder under friction.

Culture

Notable trees

A tree in Westmount, Quebec, Canada, measured in girth in 2011. The US national champion, measuring in circumference and tall, with an average crown spread of wide, grows in Kentucky. Another tall specimen grows in the Bronx, New York City, at 710 West 246th Street, measuring high in 2002.Barnard, E. S. (2002) ''New York City Trees''. New York: Columbia University Press.

Accessions

North America

* Arnold Arboretum, US. Acc. nos. 737–88 (unrecorded provenance), 172-2017 (Massachusetts), 344-2017 (Missouri).
* Bernheim Arboretum and Research Forestbr>
Clermont, Kentucky, Clermont, Kentucky, US. No details available.
* Brenton Arboretum, Dallas Center, Iowa, US. No details available.
* Chicago Botanic Garden, Glencoe, Illinois, US. 1 tree, no other details available.
* Dominion Arboretum, Ottawa, Ontario, Canada. No acc. details available.
* Longwood Gardens, US. Acc. no. L–3002, of unrecorded provenance.
* Nebraska Statewide Arboretum, US. No details available.
* Smith College, US. Acc. no. 8119PA.
* U S National Arboretumbr>
Washington, D.C., US. Acc. no. 77501.

Europe

* Brighton & Hove City Council, UK. NCCPG Elm Collection. Carden Park, Hollingdean (1 tree); Malthouse Car Park, Kemp Town (1 tree).
* Grange Farm Arboretum, Sutton St James, Spalding, Lincolnshire, UK. Acc. no. 522
* Hortus Botanicus Nationalis, Salaspils, Latvia. Acc. nos. 18168, 18169, 18170.
* Linnaean Gardens of Uppsala, Sweden. Acc. no. 2009–0223. Wild collected in US.
* Royal Botanic Gardens Wakehurst Place, UK. Acc. no. 1973–21050.
* Thenford House arboretum, Northamptonshire, UK. No details available.
* University of Copenhagen Botanic Garden, Denmark. No details available.
* Wijdemeren city council, The Netherlands. One tree planted gardens Rading 1, Loosdrecht.

Australasia

* Eastwoodhill Arboretumbr>
Gisborne, New Zealand, Gisborne, New Zealand. 1 tree, no details available.

References

External links

*

Dr. Duke's Databases: List of Chemicals in ''Ulmus rubra''

Ohio DNR.gov: Slippery Elm

''U. rubra'', Flora of North America, www.efloras.org

{{Taxonbar, from=Q1534893

rubra
Trees of Northern America
Flora of the Appalachian Mountains
Demulcents
Medicinal plants of North America
Ulmus articles with images
Elm species and varieties
Taxa named by Gotthilf Heinrich Ernst Muhlenberg