- Education and Science
Jurassic Bark - The Ginkgo Tree
Millions of years ago, dinosaurs as big as buses plowed their way through ginkgo groves, munching on the trees' leathery, fan-shape leaves as they went. Today, their fossils are the only signs that these ancient behemoths existed, but ginkgo's are still with us, unchanged from their primordial past.
Also known as the maidenhair tree, Ginkgo biloba is the sole survivor of a species of tree that grew in the carbon swamps 200 million years ago. Somehow it was caught at a period in evolution when fern-type trees were evolving into broad-leaf trees, which explains the ginkgo's unusual leaves.
Ginkgo's nearly became extinct when continents shifted and glacier encroached on the forests after the Mesozoic era.
Ginkgo or maidenhair tree is a widely cultivated and very ancient species. Apparently it died out long ago in it's native Chinese forests. About 300 years ago a specimen was discovered in a Japanese temple garden, thus it was saved from extinction.
In some cases, evolution seems to slow down to nearly a halt. Some living plants and animals seem to be just the same as their ancestors of millions of years ago. For this reason they are called 'living fossils'.
Long before evolution of the modern conifers or broad leafed trees, ginkgoes populated temperate forests all over the world. Fossil imprints have been found to substantiate this in many parts of the world, from the United States to Australia to Germany. This fossil evidence shows that it has survived unchanged for around 200 million years, giving it a truly ancient pedigree unmatched by almost any other living organism.
Links to Ginkgo Fossils
- Ginkgo gardneri | Natural History Museum
Ginkgo gardneri is a fossil plant that has only one surviving relative - Ginkgo biloba.
- Ginkgo in Australia
After a long Australian absence, ginkgos reappeared in the Aptian Age; persisting through the Middle Cretaceous into the Turonian Age (92 million years ago).
- Ginkgo Fossil
Mesozoic Ginkgo Fossil from Siberia
- Eocene Ginkgo leaf fossils from the Pacific Northwest
- The Fossil Forum
Collection of ginkgo leaf fossils.
- Insect mimic of ginko-like leaf discovered 165 million years after its extinction
Exquisitely preserved in fossil sediments dating from the Middle Jurassic, the insect, newly named Juracimbrophlebia ginkgofolia, was discovered in 165 million-year-old deposits, as was the ginko-like tree, Yimaia capituliformis, the mimicked plant.
Ginkgo's are dioecious, meaning that male and female flowers are borne on different plants.
Male trees bear catkins that flower in spring. The female trees have smaller seed-bearing, greenish flowers, which, when pollinated grow into yellowish, plum-like fruit. It takes 20 to 50 years before a seedling tree bears fruit, and when they ripen and fall off, they give off an unpleasant smell. This is becoming a problem in cities across the world, where the females have matured, creating a smelly, slippery mess for the unwary pedestrian.
Whether the ginkgo tree still exists in a truly wild state is questionable, but is has long been planted by the Chinese as an ornamental tree. It's Chinese name Yin-Xing means 'silver fruit'. The ginkgo tree has no economical value, but have been planted in many parts of the world in parks and gardens as ornamental trees. This practice goes back a couple of hundreds of years, something that the age of some of the trees can attest to.
Ginkgo - An Icon of Ages
Today a stylized form of the ginkgo leaf appears in the modern logos of several organizations, including the city of Tokyo and Osaka University.
Family crests with a ginkgo-leaf design have been used in Japan since the Middle Ages. These crests typically appeared on ceremonial kimonos, temples, shrines, sword guards, gravestones, roof tiles, gates and castle walls. Between the 17th and 19th centrures, ginkgo appeared as a motif on swords, hand mirrors, ceramics and the hand guards on Samurai swords (tsuba)
Today, the ginkgo leaf remains a popular motif on ceramic plates and vases, paintings, woodcarvings kimonos, prints, textiles, and so much more. It has come represent beauty and an acknowledgement to age long traditions.
It is not surprising that a tree of such antiquity has collected its share of legends. It is said, for example, that if you make a wish while touching a ginkgo, it will come true. Another legend claims the tree exude moisture as a gesture of loyalty when their owner's house is in danger of fire. Regardless of the veracity of such myths, the tree possesses a unique beauty.
Ginkgo in Medicine
With all the hype on the internet today about the medicinal benefits of using herbs, I couldn't help but add some of the findings I came across.
Though it has long been used as a medicine in its native China, its therapeutic actions have only recently been researched.
In Chinese herbal medicine ginkgo seeds are used to relieve wheezing and to lessen phlegm. They are also given to treat vaginal discharge, a weak bladder, and incontinence. The leaves are traditionally used for treating asthma.
Western herbal medicine has mostly concentrated on the remarkable ability of the leaves to improve the circulation, especially poor circulation to the brain. The herb's anti-allergenic and anti-inflammatory actions also make it a particularly useful remedy for the treatment of asthma.
Ginkgo is one of the best selling herbal medicines in France and Germany, where it is taken daily by millions of people from middle age onward to maintain and improve cerebral circulation and the memory. It is also taken to reduce the possibility of a stroke.
As with all things in nature, it has a good side and a bad side. Here are some of the side effects and cautions you should know about. I would also recommend further, extensive research into any herbal remedy you wish to try.
Side Effects and Cautions of Ginkgo
- Side effects of ginkgo may include headache, nausea, gastrointestinal upset, diarrhea, dizziness, or allergic skin reactions. More severe allergic reactions have occasionally been reported.
- There are some data to suggest that ginkgo can increase bleeding risk, so people who take anticoagulant drugs, have bleeding disorders, or have scheduled surgery or dental procedures should use caution and talk to a health care provider if using ginkgo.
- Fresh (raw) ginkgo seeds contain large amounts of a chemical called ginkgotoxin, which can cause serious adverse reactions—even seizures and death. Roasted seeds can also be dangerous. Products made from standardized ginkgo leaf extracts contain little ginkgotoxin and appear to be safe when used orally and appropriately.
- Tell all your health care providers about any complementary health practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Ginkgo Links in Medicine
- Herbal Medicine: Ginkgo -- Ancient Medicine, Modern Medicine
The healing traditions of ginkgo were recorded from thousands of years ago when the seeds were used in medicinal preparations.
- Science-Based Medicine - Ginkgo biloba – No Effect
Published in JAMA this week are the results of the largest and longest trial to date of Gingko biloba for the improvement of cognitive function and to treat, prevent, or reduce the effects of Alzheimers disease or other dementia.
- Ginkgo Biloba - by the Free Online Medical Dictionary
Definition of Ginkgo Biloba in the Medical Dictionary.
- Ginkgo medical facts from Drugs.com
Physician reviewed ginkgo patient information - includes ginkgo description, dosage and directions.