Ulmus gaussenii

Ulmus gaussenii W. C. Cheng, the Anhui, or hairy, elm, is a medium size deciduous tree whose natural range is restricted to the valleys of the Langya limestone mountains of Chu Xian[2] in Anhui Province, eastern China.[3] The tree was most commonly found on the flood plains, indicating a tolerance of periodic inundation. However, U. gaussenii is now possibly the rarest and most endangered elm species, with only approximately 30 trees known to survive in the wild in 2009.[4] The tree was introduced to the West in 1995, at the Morton Arboretum, Illinois, as part of an evaluation of Chinese elms for landscape use.[5]

Ulmus gaussenii
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Ulmaceae
Genus: Ulmus
Species:
U. gaussenii
Binomial name
Ulmus gaussenii

Description

The tree can grow to a height of about 25 m, with a slender trunk < 0.8 m d.b.h. The bark is longitudinally fissured and almost black. The leaves are generally obovate, < 11 cm long, borne on densely pubescent reddish twigs, sometimes featuring flat corky wings. The wind-pollinated apetalous flowers appear in March, the large orbicular samarae < 28 mm in diameter ripen in April.[6][7] Autumn colour of the foliage is a deep crimson.[8]

  • Leaf of U. gaussenii, Great Fontley, UK
  • Foliage of U. gaussenii, Great Fontley, UK

Pests and diseases

The tree is resistant to Dutch elm disease and the elm leaf beetle Xanthogaleruca luteola.[9]

Cultivation

The species is cultivated in Jiangsu (Nanjing),[7] but remains very rare in cultivation in the West. In artificial freezing tests at the Morton Arboretum the LT50 (temp. at which 50% of tissues die) was found to be -30.7 °C.[10] The Anhui elm was considered of particular interest, as its riparian habitat suggests it tolerates anoxic ground during prolonged flooding.[11] Very few specimens are cultivated (2019) in Europe, notably in the UK and the Netherlands. There are no known cultivars of this taxon, nor is it known to be in commerce.

Etymology

The tree was named in 1939 for Marcel-Henri Gaussen (1891–1981), a French botanist who travelled widely in Asia.[12]

Accessions
North America

Europe

References
  1. World Conservation Monitoring Centre (1998). "Ulmus gaussenii". IUCN Red List of Threatened Species. 1998: e.T32460A9708715. doi:10.2305/IUCN.UK.1998.RLTS.T32460A9708715.en. Retrieved 11 January 2018.
  2. Geographical Names: Chu Xian, Anhui, satellite photograph. National Geospatial-Intelligence Agency, Bethesda, MD, USA
  3. Fu, L. and Xin, Y. 'Elms of China' in Dunn, C. P. (ed.) (2000). The Elms - Breeding, Conservation, and Disease Management., Part 1, Taxonomy, 21-44. Springer Science + Business Media, New York. ISBN 978-1-4613-7032-1
  4. Grimshaw, J. & Bayton, R. (2009). New Trees - Recent Introductions to Cultivation. RBG Kew, London. ISBN 978-1-84246-173-0
  5. Ware, G. (1995). Little-known elms from China: landscape tree possibilities. Journal of Arboriculture, (Nov. 1995). International Society of Arboriculture, Champaign, Illinois, US. Archived 2007-11-30 at the Wayback Machine
  6. Fu, L. & Jin J. (eds). (1992). China Red Data Book. Rare and endangered plants. Vol. 1. Science Press, Beijing
  7. 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.
  8. Brookes, A. H. (2020). Great Fontley Elm Trial, 2020 Report. Butterfly Conservation, Lulworth, England.
  9. "Elm Leaf Beetle Survey". Archived from the original on 2011-07-19. Retrieved 17 July 2017.
  10. Shirazi, A. M. & Ware, G. H. (2004). Evaluation of New Elms from China for Cold Hardiness in Northern Latitudes. International Symposium on Asian Plant Diversity & Systematics 2004, Sakura, Japan.
  11. Dirr, M. (2009). 'Future Tree Selections'. Western, Spring 2009,  p.8. Western Nursery & Landscape Association, St Joseph, Missouri.
  12. Cheng, W. C. (1939). 'Ulmus gaussenii'. Travaux du Laboratoire Forestier de Toulouse. 3(3): 110. 1939.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.