Ulmus bergmanniana explained

Ulmus bergmanniana C.K.Schneid.,^[1] commonly known as Bergmann's elm, is a deciduous tree found across much of China in forests at elevations of 1500 - 3000 m.^[2]

Description

The tree is very closely related to the wych elm Ulmus glabra;^[3] it can reach a height of with a wide-spreading crown, and a trunk of about 0.9 m d.b.h.^[4] The bark is longitudinally fissured, and varies in colour from greyish-white to dark grey.^[5] The pubescent leaves range from obovate to elliptic, less than 16cm (06inches) long, and bluish-green when mature.^{[6] [7] [8]} Schneider's leaf-drawing (1907) shows a short wych-like petiole.^[9] The perfect, wind-pollinated apetalous flowers are produced on second-year shoots in February,^[10] followed by generally obovate samarae <30 mm long by 14 mm width, the centre of the seed about 7 mm from the slightly notched apex.^[11] Branchlets do not possess the corky wings characteristic of many other elm species.

Pests and diseases

U. bergmanniana has a moderate resistance to Dutch elm disease; in trials ^[12] in Oklahoma it was also found to be eschewed by the elm leaf beetle Xanthogaleruca luteola http://commons.wikimedia.org/wiki/Xanthogaleruca_luteola, but further north at the Morton Arboretum was moderately to highly preferred by the insect. The species is also susceptible to the elm leafminer.^[13]

Cultivation

The tree was introduced to the West in 1900. In trials in the USA it was found to propagate well, and also proved to be very winter hardy. The tree was one of 12 Chinese species under evaluation at the Morton Arboretum, Illinois, in 2009 by the late Dr George Ware.^{[14] [15]} There are no known cultivars of this taxon.

Subspecies & varieties

Two varieties are recognized: var. bergmanniana L.K.Fu, and var. lasiophylla C.K.Schneid..

Etymology

The species was named by Camillo Karl Schneider for his friend Carl Bergmann, who assisted in indexing the work in which it was published.^[1]

Accessions

North America

• Brenton Arboretum, US.
• Chicago Botanic Garden, US. Planted in West Collections Area.
• Denver Botanic Gardens, US. No acc. no. available.
• Morton Arboretum, US. acc. no. 44-95. Obtained from Yunnan Province, China.
• United States National Arboretum, Washington, D.C., US. Acc. nos. 68997, 76216, 76217, 76242, 68977.

Europe

• Wijdemeren City Council, Netherlands. Elm collection. Planted 2013 Smeerdijkgaarde, Kortenhoef.

Nurseries

Europe

• Pan-Global Plants http://www.panglobalplants.com/, Frampton-on-Severn, Gloucestershire, UK.

External links

• U. bergmanniana description, efloras.org
• U. bergmanniana leaves and fruit illustration, efloras.org
• Photographs (tree, leaves and fruit) labelled U. bergmanniana (18 pages) on Plant Photo Bank of China, ppbc.iplant
• U. bergmanniana, Kew Gardens 'Plants of the World Online' (herbarium specimen not matching efloras illustration above)
• U. bergmanniana description, and photographs labelled Bergmann's elm, ulmen-handbuch.de

Notes and References

1. https://archive.org/details/mobot31753002689096/page/901/mode/2up Schneider, Camillo Karl, Illustriertes Handbuch der Laubholzkunde (Jena, 1907), p.902
2. Web site: Ulmus bergmanniana_EOL.
3. , Richens, R. H., Elm (Cambridge, 1983), p.87
4. 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. http://flora.huh.harvard.edu/china/PDF/PDF05/Ulmus.pdf
5. http://ppbc.iplant.cn/tu/6018166''U. bergmanniana bark photograph, Xianyang City, Yangling District, Shaanxi Province, China; ppbc.iplant.cn/
6. Web site: Photograph labelled U. bergmanniana, asianflora Ulmaceae.
7. White, J. & More, D. (2003). Trees of Britain & Northern Europe. Cassell's, London.
8. Web site: Herbarium catalogue. Ulmus bergmanniana - 1. Board of Trustees of the Royal Botanic Gardens, Kew. 17 October 2016.

   Web site: Herbarium catalogue. Ulmus bergmanniana - 2. Board of Trustees of the Royal Botanic Gardens, Kew. 17 October 2016.

9. https://archive.org/details/mobot31753002689096/page/903/mode/2up Schneider, Camillo Karl, Illustriertes Handbuch der Laubholzkunde (Jena, 1907), p.903-904
10. https://vplants.org/portal/collections/individual/index.php?occid=24480413 Campbell University Herbarium specimen. Sheet labelled U. bergmanniana Schneid., flowers from Morton Arboretum (2011)
11. Sheet labelled U. bergmanniana Schneid., new leaves and samarae, Kew Gardens specimen (1960)
12. Web site: Elm Leaf Beetle Survey. 17 July 2017. https://web.archive.org/web/20110719132152/http://www.sunshinenursery.com/survey.htm. 2011-07-19.
13. Grimshaw, J. & Bayton, R. (2009). New Trees - Recent Introductions to Cultivation. RBG Kew, London.
14. Dirr, M. (2009). 'Future Tree Selections'. Western, Spring 2009,  p.8. Western Nursery & Landscape Association, St Joseph, Missouri.https://www.yumpu.com/en/document/view/52250445/dr-michael-a-dirr-offering-future-tree-selections/4
15. https://www.cirrusimage.com/tree_bergmanns_elm/ Bergmann's elm at Morton Arboretum; cirrusimage