Ulmus crassifolia

Description

The cedar elm is a medium to large deciduous tree growing to 24–27 m tall with a rounded crown. The leaves are small, 2.5–5 cm long by 1.3–2 cm broad, with an oblique base, and distinguish it from Ulmus serotina with which it readily hybridizes in the wild. Leaf fall is late, often in early winter. The wind-pollinated apetalous perfect flowers are produced in the late summer or early fall; they are small and inconspicuous, with a reddish-purple color, and hang on slender stalks a third to a half inch long. The fruit is a small winged samara 8–10 mm long, downy on both surfaces at first, maturing quickly after the flowering in late fall. Image:Ulmus crassifolia (USDA).jpg|U. crassifolia bark File:Ulmus_crassifolia_kz02.jpg|U. crassifolia foliage, Botanischer Garten, Berlin-Dahlem File:Winged Elm Ulmus alata 2009-05-10.jpg|U. crassifolia branchlet, Spring Creek, Garland, Texas Ulmus crassifolia leaves.jpeg|U. crassifolia leaves and fruit, November File:MonarchButterfly-5635.jpg|Migrating monarch butterflies on a cedar elm in central Texas

Pests and diseases

Cedar elm is susceptible to Dutch elm disease (DED), though less so than American elm, and moderately damaged by the elm leaf beetle Xanthogaleruca luteola. The tree also suffers from a vascular wilt, the symptoms often confused with those of DED.

Cedar elms are very susceptible to mistletoe. Mistletoe is a parasite that roots itself into the vascular system of the tree, thus stealing valuable nutrients and water. In some cases, if not removed, the parasite can be devastating to large sections of trees and even fatal. They create club-like branches that die out at the ends. These "club" branches create openings for future pests such as the elm beetles and carpenter ants. No treatments are known to be safe enough to kill mistletoe without killing the tree. Removing the mistletoe manually is not a guarantee, but it is the best-known method for control.

Cedar elms are known to be highly immune to Texas root rot caused by the fungus Phymatotrichopsis omnivora. Because of this, it is usually planted in regions where P. omnivora is prevalent, since the closely related lacebark elm is highly susceptible and easily killed by the fungus.

Cultivation

U. crassifolia is extremely rare in cultivation in Europe and Australasia. Specimens were supplied by the Späth nursery of Berlin from the late 19th century. Henry (1913) and Bean (1988) note that it does not thrive in northern Europe, where the branchlets often die back. Three trees supplied by Späth to the Royal Botanic Garden Edinburgh in 1902 as U. crassifolia may survive in Edinburgh, as it was the practice of the garden to distribute trees about the city (viz. the Wentworth elm).

Notable trees

The US national champion, measuring 37 m high in 2001, grows in the Meeman-Shelby Forest State Park, Tennessee.http://www.americanforests.org/our-programs/bigtree

Cultivars

• 'Brazos Rim'.

Hybrids

• Ulmus × arkansana [: U. crassifolia × U. serotina ]. Present in Arkansas and Oklahoma.

Accessions

North America

• Arnold Arboretum, US. Acc. nos. 511–2002, 758–86, both wild collected
• Chicago Botanic Garden, US. No details available.
• Bartlett Tree Experts, US. Acc. no. 90–1243, unrecorded provenance.
• Morton Arboretum, US. Acc. no. 385–68, 14-86
• New York Botanical Garden, US. Acc. no. 79617, unrecorded provenance.
• U S National Arboretum, Washington, D.C., US. Acc. no. 37834

Europe

• Grange Farm Arboretum, Lincolnshire, UK. Acc. no. 509
• Royal Botanic Garden Edinburgh, UK. Acc. no. 20080090, from seed wild collected in US.
• Sir Harold Hillier Gardens, UK. Acc. no. 1980–0443, (Brentry Field).
• University of Copenhagen Botanic Garden, Denmark. No details available.

Australasia

• Manukau Cemetery & Crematorium, Auckland, New Zealand. No details available.

Nurseries

North America

Widely available

Europe

• Arboretum Waasland, Nieuwkerken-Waas, Belgium.

Australasia

None known.

References

References

1. Barstow, M.. (2017). "''Ulmus crassifolia''".
2. "Map: Ulmus crassifolia". Efloras.org.
3. Todzia, C. A. & Panero, J. L. (2006). A new species of Ulmus (Ulmaceae) from southern Mexico and a synopsis of the species in Mexico. ''Brittonia'', Vol 50, (3): 346
4. (1998). "A New Species of Ulmus (Ulmaceae) from Southern Mexico and a Synopsis of the Species in Mexico". Brittonia.
5. (22 February 2011). "The many beneficial traits of cedar elm".
6. "Ulmus crassifolia in Flora of North America @". Efloras.org.
7. "Ulmus crassifolia".
8. 9781108069380
9. (2003). "Auckland's elms". Auckland Botanical Society.
10. [https://archive.org/details/Spaeth104.1899 Späth, L., Catalogue 104 (1899–1900; Berlin), p.133]
11. Bean, W. J. (1988) ''Trees and shrubs hardy in Great Britain'', 8th edition, Murray, London
12. {{Royal Botanic Garden Edinburgh
13. (1902). "Accessions book". Royal Botanic Garden Edinburgh.
14. American Forests. (2012). The 2012 National Register of Big Trees.
15. [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501330 ''U.'' × ''arkansana'' information in ''U. serotina'' article, efloras.org]
16. [https://vplants.org/portal/collections/individual/index.php?occid=11306602&clid=0 Herbarium specimen labelled ''U. crassifolia'' × ''U. serotina''], St. Francis County, Arkansas, 1967; Duke University Herbarium no. 10074806
17. [https://vplants.org/portal/collections/individual/index.php?occid=11464963&clid=0 Herbarium specimen labelled ''U. crassifolia'' × ''U. serotina''], St. Francis County, Arkansas, 1967; Tulane University Herbarium no. 0048399
18. [https://vplants.org/portal/collections/individual/index.php?occid=6342716&clid=0 Herbarium specimen labelled ''U. crassifolia'' × ''U. serotina''], St. Francis County, Arkansas, 1967; Mississippi Museum of Natural Science Herbarium no. 002200
19. [https://vplants.org/portal/collections/individual/index.php?occid=29440631&clid=0 Herbarium specimen labelled ''U. crassifolia'' × ''U. serotina''], St. Francis County, Arkansas, 1967; Mississippi State University Herbarium no. 036765
20. [https://vplants.org/portal/collections/individual/index.php?occid=21193122&clid=0 Herbarium specimen labelled ''U.'' × ''arkansana'' (?)], Pulaski County, Arkansas, 2016; Arkansas Natural Heritage Commission Herbarium no. 009182
21. [https://vplants.org/portal/collections/individual/index.php?occid=15445797&clid=0 Herbarium specimen labelled ''U.'' aff. ''crassifolia'', probably ''U. × arkansana''], Pulaski County, Arkansas, 2012; Austin Peay State University Herbarium no. 0053465
22. (2010-05-06). "''Ulmus crassifolia'' at Morton Arboretum". Cirrusimage.com.
23. Ramon Jordan. "US National Arboretum". Usna.usda.gov.
24. "English". Arboretum-waasland.be.