Ulmus szechuanica: Difference between revisions
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==Description== |
==Description== |
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[[Image: Szechuanica leaves.jpg|thumb|left|140px]] |
[[Image: Szechuanica leaves.jpg|thumb|left|140px]] |
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The tree 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 [[apetalous]] flowers are produced on second-year shoots in February, followed by suborbicular [[Samara (fruit)|samarae]] < 16 mm by 13 mm in March <ref name=Fu,a>Fu, L. & Jin J. (eds). (1992). ''China Red Data Book. Rare and endangered plants. Vol. 1''. Science Press, Beijing.</ref> <ref name=Fu,b>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]</ref>. |
The tree 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 [[leaf shape|obovate]] < 9 cm long by 5 cm broad, borne on branchlets with an irregular corky layer. The wind-pollinated [[apetalous]] flowers are produced on second-year shoots in February, followed by suborbicular [[Samara (fruit)|samarae]] < 16 mm by 13 mm in March <ref name=Fu,a>Fu, L. & Jin J. (eds). (1992). ''China Red Data Book. Rare and endangered plants. Vol. 1''. Science Press, Beijing.</ref> <ref name=Fu,b>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]</ref>. |
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==Pests and diseases== |
==Pests and diseases== |
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''U. szechuanica'' was evaluated with other Chinese elms at the [[Morton Arboretum]], [[Illinois]], where it exhibited a resistance to [[Dutch elm disease]]. The species is eschewed by the Elm Leaf Beetle ''[[Xanthogaleruca luteola]]'' [http://www.sunshinenursery.com/survey.htm]. |
''U. szechuanica'' was evaluated with other Chinese elms at the [[Morton Arboretum]], [[Illinois]], where it exhibited a resistance to [[Dutch elm disease]]. The species is eschewed by the Elm Leaf Beetle ''[[Xanthogaleruca luteola]]'' [http://www.sunshinenursery.com/survey.htm]. |
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Revision as of 13:01, 3 November 2008
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| Ulmus szechuanica, Sir Harold Hillier Gardens | |
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| Species: | U. szechuanica
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| Ulmus szechuanica Fang
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Ulmus szechuanica Fang, known as the Szechuan (Sichuan), or Red-fruited, Elm, is a small to medium deciduous Chinese tree found along the Yangtze river through the provinces of Sichuan, Jiangxi, Anhui, and Jiangsu.
Description
The tree 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 apetalous flowers are produced on second-year shoots in February, followed by suborbicular samarae < 16 mm by 13 mm in March [1] [2].
Pests and diseases
U. szechuanica was evaluated with other Chinese elms at the Morton Arboretum, Illinois, where it exhibited a resistance to Dutch elm disease. The species is eschewed by the Elm Leaf Beetle Xanthogaleruca luteola [3].
Cultivation
Growing best on well-drained soils,U. szechuanica is also cold hardy; in artificial freezing tests at the Morton 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.
Accessions
- 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 [4],
- Grange Farm, Sutton St. James, Spalding, Lincolnshire, UK, acc. no. 523
- Sir Harold Hillier Gardens, UK, acc. no. 1994.0329, one tree, 4.4 m tall in 2008, from seed from the Shanghai Botanic Garden [5].
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.