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|Eucommia ulmoides foliage and flowers.|
Eucommia ulmoides is a species of small tree native to China. It belongs to the monotypic family, Eucommiaceae. It is near threatened in the wild, but is widely cultivated in China for its bark and is highly valued in herbology such as Traditional Chinese medicine.
Eucommia ulmoides grows to about 15 m tall. The leaves are deciduous, arranged alternately, simple ovate with an acuminate tip, 8–16 cm long, and with a serrated margin. If a leaf is torn across, strands of latex exuded from the leaf veins solidify into rubber and hold the two parts of the leaf together. It flowers from March to May. The flowers are inconspicuous, small and greenish; the fruit, June to November, is a winged samara with one seed, very similar to an elm samara in appearance, 2–3 cm long and 1–2 cm broad.
Eucommia ulmoides is the sole living species of the genus Eucommia. Eucommia is the only genus of the family Eucommiaceae, and was formerly considered to be a separate order, the Eucommiales. It is also sometimes known as "Gutta-percha tree" or "Chinese rubber tree", but is not related to either the true Gutta-percha tree of southeastern Asia, nor to the South American rubber tree.
Eucommia ulmoides is also occasionally planted in botanical gardens and other gardens in Europe, North America and elsewhere, being of interest as the only cold-tolerant (to at least -30°C) rubber-producing tree. Fossils of other Eucommia species have been found in 10–35 million year old brown coal deposits in central Europe and widely in North America (Call & Dilcher 1997), indicating that the genus had a much wider range in the past.
It is one of the 50 fundamental herbs used in Chinese herbology, where it is called dùzhòng (Chinese: 杜仲). Because of the low production and high demand for natural rubber in China, a unique process has been developed to manufacture elastic materials with Eucommia ulmoides gum (EUG) as substitutes for natural rubber products. Unlike the latex used to produce natural rubber, the EUG is the polymer trans-1,4-polyisoprene. Thus materials made from EUG may demonstrate characterics other than those of natural rubber , such as higher elastics, lower thermoplastic temperature, etc.
The iridoid glucoside geniposidic acid can be found in E. ulmoides.
- Chinese herbology 50 fundamental herbs
- Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III" (PDF). Botanical Journal of the Linnean Society 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. Retrieved 2013-07-06.
- "IPNI Plant name details Eucommia". Retrieved 9 September 2013.
- "IPNI Plant name details Eucommia ulmoides". Retrieved 9 September 2013.
- World Conservation Monitoring Centre (1998). Eucommia ulmoides. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006.
- Call, V.B. and Dilcher, D.L. 1997. The fossil record of Eucommia (Eucommiaceae) in North America. American Journal of Botany 84(6): 798-814. Available online (pdf file)
- HUEC Nutrition & Obesity (including Eucommia bark results) online (ppt)
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Data related to Eucommia ulmoides at Wikispecies