Amur Cork—Landscape Lovely or Harmful Invader?

First brought to the United States in 1856

OLYMPUS DIGITAL CAMERA
Amur cork tree

Amur cork  tree (Phellodendron amurenses) is native to China, Korea, and other areas of Asia. It was first brought to the United States in 1856 and grown in the Harvard Botanic gardens as early as 1908. From 1933 it has been reported to have naturalized in New York. Currently it is considered an invasive plant in a number of states. As an invasive plant it crowds out native trees and produces berries which are less nutritious than the nuts of native trees; its berries do not have the same essential fats needed for wildlife to survive through the winter.

OLYMPUS DIGITAL CAMERA
Leaves of the Amur cork tree

Some of the sources referenced above speculate that the trees were brought from Asia by railroad workers. The trees’ growth patterns have contributed to its “success” in crowding out native specie. By suppressing the growth of canopy trees, it has become one of the dominate trees in eastern states. Although many states warn against planting Amur cork, others suggest Phellodendron amurenses is a good landscape variety. A few suggest only male trees be considered. This might be a reasonable solution in areas were there are no others, but in areas where the trees have naturalized, the male tree may still fertilize female trees and add to the problem.

Possibly one of the reasons Amur Corks were originally brought to North America is that it is considered to be one of the fifty most important herbs used in Chinese medicine. Some of its compounds have been used to treat meningitis, arthritis, cancers, and diseases of the lungs. The Ainu population of Japan also used parts of this tree as a painkiller.

WebMD mentions most of the uses above. It also states some of the trees’ compounds, such as berberine, might lower blood sugar and LDL cholesterol. At the same time they include warnings about possible harmful effects. There is limited scientific research to support usage.

Other non-medicinal uses have been mentioned; older literature suggests the bark as a substitute for cork.

OLYMPUS DIGITAL CAMERA
The corky trunk of the Amur Cork Tree

It may be used for cork in Russia. An oil made from seeds may have insecticidal properties. A yellow dye obtained from inner layers of bark, was used to produce yellow-tinted paper, useful in distinguishing the important of various Chinese documents.

The Amur cork tree (C138) may be found in City Park  where Olive Street intersects with Jackson Street. As can be seen in the photo at the beginning of this post, the tree is almost directly across from Olive Street street.