Ulmus rubra

The Slippery Elm (Ulmus rubra^[1]) is a species of elm native to eastern North America (from southeast North Dakota, east to southern Quebec, south to northernmost Florida, and west to eastern Texas). It is similar to American Elm in general appearance, but more closely related to the European Wych Elm, which has a very similar flower structure. It is less susceptible to Dutch elm disease than other elms and has a different branching pattern. Its heartwood is reddish-brown, giving the tree the name, Red Elm. Other names include Gray Elm, Soft Elm, Moose Elm and Indian Elm.

  The Slippery Elm is a deciduous tree which reaches 10-20 m tall and has a 50 cm trunk diameter. The leaves are 10-18 cm long and have rough texture, coarsely double-serrate margin and an oblique base. The flowers are produced before the leaves in early spring, usually in clusters of 10-20. The fruit is an oval winged samara 2 cm long and containing a single, central seed. Slippery Elm may be distinguished from American Elm by the hairiness of the buds and twigs (American Elm has smooth buds and twigs) and by the flowers being very short-stalked.

Slippery Elm grows well in moisture-rich uplands, but it will also grow in dry, intermediate soils^[2].

Additional recommended knowledge

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Uses

Slippery Elm is a valuable tree that has many traditional uses. The inner bark can be ground into a nutrient-rich gruel, off of which one can solely survive for a short period. The bark also contains a mucilage that is used as a remedy for sore throats. Sometimes it is dried and ground into a powder beforehand, then made into a tea. Both Slippery Elm gruel and tea are said to soothe the digestive tract, especially the GI tracts of those with irritable bowel syndrome or gastritis. There are no known contraindications for Slippery Elm. It is also not technically a drug because it is mainly mucilage and various nutrients. ^[3]

The bark has also been used historically as an abortifacient, first moistened with water and then inserted into the cervix. This practice became thoroughly regulated by "elm stick laws" in several US states, which forbade selling pieces of slippery elm bark longer than a certain length. Selling whole Slippery Elm bark is banned in several countries including the UK because of this.

The fibrous inner bark is a strong and durable fibre, which can be spun into thread, twine or rope. It can be used for bow strings, ropes, jewellery, clothing, snowshoe bindings, woven mats, and even some musical instruments.

The wood is used for the hubs of wagon wheels, as it is very shock resistant owing to the wood's interlocking grain.

Once cured, the wood is also excellent for making fires with the bow drill method, as it grinds into a very fine, flammable powder under friction.

Hybrid cultivars

U. rubra had limited success as a hybrid parent in the 1960s, but nonetheless resulted in Coolshade, Lincoln, Rosehill, and probably Willis hybrids ^[4]. In later years, it was also used in the Wisconsin programme to produce Repura and Revera ^[5] although neither appear to have been commercially released (2007).

Arboreta etc. accessions

North America

• Arnold Arboretum, acc. nos. 737-88, 738-88, both of unrecorded provenance.
• Bernheim Arboretum and Research Forest [1], Clermont, Kentucky. No details available.
• Brenton Arboretum, Dallas Center, Iowa. No details available.
• Longwood Gardens, acc. no. L-3002, of unrecorded provenance.
• Smith College, acc. no. 8119PA.

Europe

• Brighton & Hove City Council,NCCPG elm collection [2].
• Grange Farm, Sutton St. James, Spalding, Lincolnshire, UK, acc. no. 522
• Hortus Botanicus Nationalis, Salaspils, Latvia acc. nos. 18168, 18169, 18170.
• Royal Botanic Garden Wakehurst Place, acc. no. 1973-21050.
• Thenford House arboretum, Northamptonshire, UK, no details available.
• University of Copenhagen Botanic Garden (no details available)

Australasia

• Eastwoodhill Arboretum [3], Gisborne, New Zealand, 1 tree, details not known.

Nurseries

Europe

• Grange Farm Plants, Spalding, Lincs., UK.
• Salley Gardens, UK.
• Arne Herbs, UK.

Seed suppliers

• B and T World Seeds, Paguignan, 34210 Aigues-Vives, France

Gallery

References

1. ^ Gotthilf H E Muhlenberg
2. ^ http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/ulmus/rubra.htm
3. ^ Supplement Watch
4. ^ Green, P S (July 1964). "Registration of cultivar names in Ulmus". Arnoldia 24 (6-8): 41-46.
5. ^ Santamour, Frank S; Susan E Bentz (May 1995). "Updated checklist of elm (Ulmus) cultivars for use in North America". Journal of Arboriculture 21 (3): 122-131.