Ulmus szechuanica

Ulmus szechuanica
	Ulmus szechuanica leaves, summer
Conservation status
	Endangered
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Ulmaceae
Genus:	Ulmus
Species:	U. szechuanica
Binomial name
	Ulmus szechuanica; Fang
Synonyms
	Sichuan Elm Morton Arboretum; Ulmus erythrocarpa W. C. Cheng;

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].

Cultivars

None known.

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

Sunshine Nursery [4], Clinton, Oklahoma.

Europe

None known

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.

[Fu,a-1] Fu, L. & Jin J. (eds). (1992). China Red Data Book. Rare and endangered plants. Vol. 1. Science Press, Beijing.

[Fu,b-2] 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-3] 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-4] 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-5] Mittempergher, L. & Santini, A. (2004). Elm breeding history. Invest Agrar: Sist Recur For, (2004), 13 (1), 161-177.

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