Eucommia

Not to be confused with Eucosmia or Eucosma.

Eucommia
Eucommia ulmoides foliage and flowers.
Conservation status
Near Threatened (IUCN 2.3)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Garryales
Family:	Eucommiaceae Engler
Genus:	Eucommia Oliv.
Species:	E. ulmoides
Binomial name
Eucommia ulmoides Oliv.

Eucommia (Eucommia ulmoides) is a small tree native to China. It is near threatened in the wild, but is widely cultivated in China for its bark, highly valued in herbology such as Traditional Chinese medicine (TCM).

Characteristics

Eucommia is the sole member of the family Eucommiaceae, and was formerly considered to be a separate order, the Eucommiales. It is one of the 50 fundamental herbs used in Chinese herbology, where it is called dùzhòng (Chinese: 杜仲).

Growth

Eucommia 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.

Distribution

Eucommia 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 Eucommia 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.

Synonymy

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.

Ethnomedicinal use

The bark is used in traditional Chinese medicine to treat lower back pain and aching knees, to prevent miscarriage and to "tonify" the yang.^{[citation needed]}

Beta blocker

Frank Greenway of the Pennington Biomedical Research Center has shown that an extract of Eucommia acts as a beta-adrenergic blocking agent, but further studies are needed to clarify its adrenergic properties.^{[citation needed]} In Greenway's studies Eucommia bark (500 mg, three times a day) gave 5 mmHg blood pressure reduction compared to controls (placebo).^{[citation needed]}

See also

• Chinese herbology 50 fundamental herbs

References and external links

• 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)