Trees: Ginkgo

 

Trees: Ginkgo

 

Images of Gingko leaves have been found captured in layers of sedimentary rocks dating back 270 million years ago to the Permian Age. The trees have been called “living fossils”because of the ancient paleontology records. The genus first appears in the Early Jurassic and gets spread throughout Laurasia during the Middle Jurassic and Early Cretaceous. But suddenly the paleontological record crashes during the Paleocene, and by the Pliocene, the only Ginkgo left on earth were in a small isolated area of central China, where the species survived to the modern era.[1]

 

 

Also known as the maidenhair tree, the Gingko has soft green leaves with hair-like strands that extend the entire length of the leaf petals. It is believed to be one of the oldest trees in the Earth’s history, and human history for that matter. Native to mainland China, Ginkgoes have been cultivated for their multiple uses in traditional Chinese medicine and as a source of food.[2]

 

Ginkgo grove outside Morse College, Yale

 

The first time I remember seeing Ginkgoes was in New Haven, Connecticut. Living in Morse College, a small grove of Ginkgoes had been planted between Morse and Ezra Styles on both sides of the pathway that directed towards the Payne Whitney Gym. Nearly every day, I would walk by the trees and admire their shade, their color, and their leaves. Turning bright yellow in the fall, they were always fun to see as they turned color and soon covered the ground with a golden carpet. The fallen fruit of the female tree, on the other hand, smelled like rancid butter or vomit as the seeds and fruit were spattered underfoot along the path. Not all of the trees were female, thank goodness, but enough bore fruit to leave an indelible olfactory impression.

 

  Ginkgo in Courtyard at Yale

 

Chinese “Island”

 

The Latinate name for the Ginkgo biloba tree is strange indeed, the result of a spelling error by one of the first Westerners to investigate the species back in the 1690’s, Engelbert Kaempfer. He apparently took the spelling from the Japanese, rather than from the more precise translation of “ginkio” or “ginkjo.” The error has been promulgated for the past 325 years! Biloba refers to the two (bi-) lobes (-loba), which come together to form the leaf. [3] Even stranger is the fact that there are no close living relatives of the tree; so its name, like its origin, is an island separated in time and space. 

 

 

In Chinese the names are 銀 杏, which translates as pinyin or “silver apricot”, 銀 果, which translates as “silver fruit”, and 白果, which means “white fruit.” Some specimens grow to over 160 feet in its homeland. It often has an angular crown that broadens with age and long, erratic branches. The tree has a deep root system, so it is often resistant to wind and snow damage. The root systems are aerial and combined with a natural disease-resistant bark, and insect-resistant wood, they live a long time. Some are believed to be more than 2,500 years old.[4]  Now that’s a living fossil!

 

Fall Ginkgo Leaves on Parade

 

The Ginkgo evolved in an era before flowing plants, when ferns, cycads and cycadeoids dominated the landscape. These plants thrived in places that were water was abundant, and disturbed stream-side environments were prevalent. The trees and plants formed low, open, shrub-like canopies. 

 

 

The Ginkgo has a few unusual habits in its growth that may have led to its survival: one is its very large seeds, which smell so bad on the ground that animals rarely ate them. The other trait is its habit of rapid growth with no branching. Ginkgo are known to “bolt up” 10 feet or more before sending out a side branch, making it hard for ground dwellers to munch its leaves or ripening fruit.

 

 
Growing Ginkgo

 

The Chinese have cultivated Ginkgo trees for thousands of years. Planted at many Buddhist and Confucian temples, the male trees are grafted to plants grown from seed. The males flourish without the foul smelling seeds. One of the most popular hybrids is known as “Autumn Gold”, which is a clone of the male plant. Ginkgo are also well suited to modern urban conditions, tolerating pollution, shaded places, cramped soil spaces. 

 

Ginkgo Bonsai

 

Their natural insect and disease resistance make them a natural urban dweller. Some species even tolerate the careful pruning and miniaturization that comes with bonsai art. Some plants can be kept artificially small for centuries. 

 

 

 

Cooking and Carefully Eating Ginkgo

 

Despite the malodorous fruit, the Chinese have learned to harvest the nut-like seed and to serve it in the traditional dish called congee, which is served at weddings and Chinese New Year. The nuts are also believed to have both medicinal and aphrodisiac qualities. 

 

One tricky part of a diet that includes Ginkgo nuts is that they contain a poison dubbed MPN. Scientifically called 4′-O-Methylpyridoxine, an over-consumption of MPN can make children and young adults convulse uncontrollably. Some people are also sensitive to the chemicals in the fleshy outer covering of the fruit. They break out in a blistery rash, similar to rashes caused by “poison ivy.” Wearing gloves is the preferred solution to this sensitivity. Scanning the pages of WEBMD is an eye-opener around Ginkgo, so be sure to check it out before you experience the side-effects without prior knowledge. [5]

 

 

Ginkgo & Memory

 

Of the many reported medicinal uses of Ginkgo, the most talked about ones are in the improvement of memory and the prevention of dementia. The dosages vary from 40 mg to 400 mg/day, but studies are mixed. Some studies point to a major impact improving attention with a daily dose of Ginkgo extract in healthy individuals. Other studies report no significant improvement in patients suffering from Alzheimer’s, or a variant of that trouble disease. There have been editorials in The Lancet and longitudinal studies published which have concluded that Ginkgo biloba is ineffective with both the prevention of dementia and Alzheimer’s.[6]  

 

Ginkgo biloba Memory Enhancing Tablets

 

Nevertheless, there are many devoted followers to the health effects they attribute to Ginkgo biloba, and they will not be dissuaded. I do not know the active ingredients they they claim is helping, but that is true of many concoctions from Chinese medicine.

 

In any case, it is an interesting relic of former times to have survived to thrive today. There are Ginkgo varieties all over Portland, Oregon, which are fun to admire in all seasons, but most especially in the fall.