Ulmus serotina explained

Ulmus serotina Sarg., the September elm, is an autumn-flowering North American species of tree. It is uncommon beyond Tennessee; it is only very locally distributed through Illinois, Kentucky, Arkansas, Mississippi, Oklahoma, Alabama, and Georgia, and disjunct populations into Nuevo León, Mexico. It grows predominantly on limestone bluffs and along streams to elevations of 400 m.^[1]

Description

Rarely exceeding 20 m in height, the tree has a rounded crown with spreading to pendulous branches. The glabrous young shoots become progressively corky-winged with age, and bear oblong to obovate leaves <8 cm long.^[2] The wind-pollinated apetalous perfect flowers form pendulous racemes, which open in September and serve to distinguish the species from its cogenitor, the cedar elm U. crassifolia, with which it readily hybridizes. The samarae are oblong-elliptical, 10 - 15 mm in length, deeply divided at the apex, and ripen in November http://plants.usda.gov/java/profile?symbol=ulse.

Pests and diseases

The species is highly susceptible to Dutch elm disease.

Cultivation

Before the outbreak of Dutch elm disease, U. serotina enjoyed limited popularity as a shade tree in the southern part of its range. The tree grows well on most soils, but is intolerant of anaerobic or saline conditions; it is also frost tolerant to -30°C (-23°F). The September elm is very rare in cultivation in Europe;^[3] it was briefly propagated and marketed in the UK by the Hillier and Sons nursery, Winchester, Hampshire, from 1972 to 1977, when 16 were sold.^{[4] [5]} It is not known to have been introduced to Australasia. No cultivars of this taxon are known, nor is it known to be in commerce.

Notable trees

• The current US national champion, measuring 28.65 meters high in 2013, grows in the Spring Grove Cemetery in Hamilton County, Ohio.^{[6] [7]}
• The former national champion measured at 25.5 m high in 2007, grows in Davidson County, Tennessee.^[8] http://www.americanforests.org/our-programs/bigtree

Hybrids

• Ulmus × arkansana [: ''U. serotina'' × ''U. crassifolia'' ]. Present in Arkansas and Oklahoma.^{[9] [10] [11] [12] [13] [14] [15]}

Accessions

North America

• Mildred E. Mathias Botanical Garden, UCLA, Los Angeles, California, US. (No details available)
• Morton Arboretum, US. Acc. no. 1039-23.
• U S National Arboretum http://www.usna.usda.gov/index.htm, Washington, D.C., US. Acc. no. 55431.

Europe

• Grange Farm Arboretum, Sutton St James, Spalding, Lincolnshire, UK. Acc. no. not known.
• Royal Botanic Garden Edinburgh, UK. Acc. no. 20080091, from seed wild collected in USA.^[16]
• Royal Botanic Gardens, Kew, UK. Acc. no. not known.
• Royal Botanic Gardens, Wakehurst Place, UK. Acc. no. 2006-143.
• Sir Harold Hillier Gardens, UK. Acc. no. 2004.1059, 3 trees, collected in Tennessee, 2004.
• Thenford House arboretum, Banbury, UK. No details available.
• University of Copenhagen, Botanic Garden, Denmark. No details available.

External links

• U. serotina, Flora of North America, www.efloras.org

Notes and References

1. Duncan, W. H., & Duncan, M. B. (2000). Trees of the Southeastern United States, 234 - 238. Athens, Georgia, USA.
2. Web site: Herbarium catalogue. Ulmus serotina Sarg.. Board of Trustees of the Royal Botanic Gardens, Kew. 17 October 2016.
3. Bean, W. J. (1981). Trees and shrubs hardy in Great Britain, 7th edition. Murray, London.
4. Hillier & Sons (1977). Catalogue of Trees & Shrubs. Hillier, Ampfield, UK.
5. Hillier & Sons Sales inventory 1962 to 1977 (unpublished).
6. Web site: September Elm - OH . 2023-10-03 . American Forests . en-US.
7. Web site: Spring Grove Cemetery - Champions of the Grove . Spring Grove Cemetery.
8. Web site: Ghost Trees: The champion September elm . 2023-10-03 . Vanderbilt University . en.
9. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501330 U. × arkansana information in U. serotina article, efloras.org
10. https://vplants.org/portal/collections/individual/index.php?occid=11306602&clid=0 Herbarium specimen labelled U. crassifolia × U. serotina
11. https://vplants.org/portal/collections/individual/index.php?occid=11464963&clid=0 Herbarium specimen labelled U. crassifolia × U. serotina
12. https://vplants.org/portal/collections/individual/index.php?occid=6342716&clid=0 Herbarium specimen labelled U. crassifolia × U. serotina
13. https://vplants.org/portal/collections/individual/index.php?occid=29440631&clid=0 Herbarium specimen labelled U. crassifolia × U. serotina
14. https://vplants.org/portal/collections/individual/index.php?occid=21193122&clid=0 Herbarium specimen labelled U. × arkansana (?)
15. https://vplants.org/portal/collections/individual/index.php?occid=15445797&clid=0 Herbarium specimen labelled U. aff. crassifolia, probably U. × arkansana
16. [Royal Botanic Garden Edinburgh]