Ulmus szechuanica
Ulmus szechuanica | |
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Ulmus szechuanica leaves, summer | |
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Species: | U. szechuanica
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Binomial name | |
Ulmus szechuanica Fang
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Ulmus szechuanica Fang, or Szechuan Elm is a small to medium deciduous Chinese tree found along the Yangtze river through the provinces of Sichuan, Jiangxi, Anhui, and Jiangsu. It can reach a height of 18 m, but is usually less than 10 m, with a spreading umbrella-like crown. The leaves, distinguished by their emergent red colour, are generally obovate < 9 cm long by 5 cm broad, borne on branchlets with an irregular corky layer. The wind-pollinated petal-less flowers are produced on second-year shoots in February, followed by suborbicular samarae < 16 mm by 13 mm in March [1] [2].
The tree was evaluated with other Chinese elms at the Morton Arboretum, Illinois, where it was found to grow best on well-drained soils, and exhibited a resistance to Dutch elm disease. U. szechuanica is also cold hardy; in artificial freezing tests at the arboretum [3] the LT50 (temp. at which 50% of tissues die) was found to be - 30 °C. However, it was also found to be comparatively weak-wooded, making it susceptible to storm damage in winter [4].
There are no known cultivars of this taxon, nor is it known to be available from any nurseries beyond the USA.
Hybrid cultivars
U. szechuanica is believed to have been used in recent (post 2000) hybridization experiments at the Morton Arboretum [5] but results have yet (2008) to be published.
Arboreta etc. specimens
- North America
- Chicago Botanic Garden, Glencoe, Illinois. 2 trees, no other details available.
- Denver Botanic Gardens, no details available
- Holden Arboretum, acc. nos. 96-179 (unknown provenance), 97-30 wild collected in China.
- Europe
- Brighton & Hove City Council, UK, NCCPG elm collection [3],
- Grange Farm, Sutton St. James, Spalding, Lincolnshire, UK, acc. no. 523
- Sir Harold Hillier Gardens, UK, acc. no. 1994.0329.
Nurseries
- North America
References
- ^ Fu, L. & Jin J. (eds). (1992). China Red Data Book. Rare and endangered plants. Vol. 1. Science Press, Beijing.
- ^ 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. [1]
- ^ 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.
- ^ Ware, G. (1995). Little-known elms from China: landscape tree possibilities. Journal of Arboriculture, (Nov. 1995). International Society of Arboriculture, Champaign, Illinois, USA. [2]
- ^ Mittempergher, L. & Santini, A. (2004). Elm breeding history. Invest Agrar: Sist Recur For, (2004), 13 (1), 161-177.