Maidenhair tree (Ginkgo biloba)
|Size||Height: 30 - 40 m (2)|
Diameter: 3 - 4 m (2)
Classified as Endangered (EN - B1+2c) on the IUCN Red List 2002 (1).
Ginkgo biloba, or maidenhair tree, is renowned worldwide for its medicinal properties. This remarkable tree is known as a 'living fossil', as it is the sole survivor of an ancient group of trees that date back to beyond the time of the dinosaurs (3). The maidenhair tree remains virtually unchanged today and represents the only living bridge between 'higher' and 'lower' plants (between ferns and conifers) (3). Trees reach up to 40 metres in height and older individuals tend to have a more spreading appearance with irregular branches (3). The deeply fissured, brown bark may appear cork-like in older individuals (3). Male and female trees are separate; male pollen is borne on catkin-like cones amongst the leaves whilst female ovules are more rounded (3). After fertilisation, yellowish seeds develop with a fleshy outer seed coat that resembles a plum in appearance (3). The characteristic greenish-yellow leaves are fan-shaped and composed of two or more distinct lobes; the Latin species name biloba refers to this fact (3). The common name of maidenhair tree pertains to the similarity of the leaves to those of maidenhair ferns (Adiantum spp.) (3). In autumn, the leaves of the Ginkgo tree turn a beautiful golden hue before falling to the ground (3).
The attractive maidenhair tree has been widely planted as an ornamental, and cultivated individuals exist across the world (3). Trees were traditionally planted in temple gardens in Japan and China, but today are popular in towns worldwide and are even farmed in plantations for their medicinal properties (3). The survival of wild trees however is less secure; examples can be found in China on Mount Xitianmu in the Zhejiang Province, but it is unclear whether these are the last truly wild trees or descendents from temple gardens (3).
The maidenhair tree is most suited to moist, deep, sandy soils in full sunlight but is extremely adaptable to a range of stressful conditions. Indeed, it was the first tree in the vicinity of Hiroshima to bud after the atomic bomb of 1945 (3).
It takes between 20 - 35 years for maidenhair trees to reach maturity and start bearing seeds. Pollen and ovules are produced in the spring on separate trees and, following fertilization, rounded seeds develop with a fleshy outer coat. These fall to the ground in the autumn and as the seed coat decays it exudes a rancid butter-like smell (3). Maidenhair trees can be extremely long-lived; the oldest recorded individual being 3,500 years old (3).
Ginkgo trees have been utilised for traditional medicine in Japan and China for hundreds of years. The nuts are edible if cooked and are available for sale in markets throughout the Orient; the seeds are used to treat a variety of ailments from asthma to fever (3). The extract of the Ginkgo leaves is also believed to have medicinal properties and is one of the most popular herbal remedies in the West today (4). The leaf extract has been shown to increase circulation and is used to treat a range of ailments, including Alzheimer's disease (4).
The maidenhair tree was thought to have become extinct, similarly to the other members of its ancient lineage, until it was discovered in Japan in 1691 (3). This fascinating species had persisted in the gardens of temples in the East and the first seeds were brought to Europe in the 1700s (3). The loss of the Ginkgo from the wild is likely to have been a result of deforestation, which has swept through the region (1).
It is uncertain whether the maidenhair tree still persists in the wild and at present there are no conservation projects in place. Cultivated trees are found throughout the world, however, and a multi-million dollar industry has cashed in on the leaves' medicinal properties (3). As a result, it is likely that this ancient tree will stand the test of time.
For more information on the maidenhair tree see the Ginkgo Pages:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
IUCN Red List (March, 2003)
Ginkgo biloba (March, 2003)
The Ginkgo Pages (March, 2003)
Acupuncture Today (March, 2003)