| Eucommia | |
|---|---|
| Eucommia ulmoides foliage and flowers. | |
| Conservation status | |
| 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).
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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).
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.
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.
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.
The bark is used in traditional Chinese medicine to treat lower back pain and aching knees, to prevent miscarriage and to "tonify" the yang.In traditional Chinese medicine, Eucommia bark is used to strengthen the bones and muscles and alleviate discomfort in the lower back and legs. Eucommia bark contains a substance, iridoid glycoside, that has a long history of use for inflammation.[1]One glycoside, aucubin, has been shown to be a specific inhibitor of NF-kappaB activation in mast cells, which might explain its beneficial effects.[2]
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. In Greenway's studies Eucommia bark (500 mg, three times a day) gave 5 mmHg blood pressure reduction compared to controls (placebo).