Ulmus szechuanica

Ulmus szechuanica
Ulmus szechuanica leaves, July
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Ulmaceae
Genus:	Ulmus
Species:	U. szechuanica
Binomial name
Ulmus szechuanica Fang

Ulmus szechuanica 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.

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. However, it was also found to be comparatively weak-wooded, making it susceptible to storm damage in winter. In trials in Oklahoma, it was found to be completely unaffected by elm leaf beetles [1]. Elsewhere in the USA, specimens are grown at the Denver Botanic Gardens and the Holden Arboretum. In the UK, it can be found at the Sir Harold Hillier Gardens and in the NCCPG elm collection [2] held by Brighton & Hove City Council.

U. szechuanica is now considered rare and endangered in its native China.

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. [3]
• Ware, G. (1995). Little-known elms from China: landscape tree possibilities. Journal of Arboriculture, (Nov. 1995). International Society of Arboriculture, Champaign, Illinois, USA. [4]