The Daily Apple: Apple #717: Ginkgo Trees

Yesterday, I was sitting outside a coffee house with my friend, let's call her Kiki Malone, and she noticed that the tree that was shading our table was a ginkgo tree. I turned and looked at the leaves. Seeing the distinctive fan shape, I said she was right, it was a ginkgo.

Only the ginkgo tree has leaves with a fan shape.
(Image from The Anecdotal Goat)

She said, "It's the oldest living tree in the world." Then she added, "I think. A person has to be careful saying things like that around the Apple Lady."

I said it had to get annoying, being friends with someone who often says, "Actually, according to what I learned when I did a Daily Apple on that topic. . . ." Kiki was very gracious and said it wasn't like that at all. She also said many positive and appreciative things about this here Daily Apple blog as a whole.

So, as a thank you to Kiki for saying so many nice things about the Daily Apple, here is an entry for you on ginkgo trees. And let me begin by saying: You were correct.

The Ginkgo biloba is the oldest living species of tree in the world.

Fossils of ginkgo trees have been found going as far back as 250 million years plus.

That puts the ginkgo as having been alive in the Triassic period, which suffered a massive extinction event along with enormous volcanic eruptions. Then the dinosaurs whose names most of us know showed up, and they went through their massive extinction event.

Ginkgo trees survived all of that.

Artist's rendering of what the Triassic period and its dinosaurs might have looked like. There should be some ginkgo trees in there somewhere. . . .
(Wallpaper from National Geographic)

The following characteristics may be why this tree has been able to survive for so many millennia:

No insects like to eat it or damage it

It suffers from no serious diseases

While it prefers moist, sandy soils, it will grow in just about any type of soil, even alkaline, or acidic, or compacted and not well-drained soils

It isn't bothered much by road salt, or air pollution, or occasional high temperatures

This particular ginkgo tree is a 1,400 year-old female. She lives in Jonichiji, Japan.
(Photo by Atsuko & Kunihiko Kato, on The Ginkgo Pages)

The ginkgo is singular in many other ways as well:

It is the only tree with a fan-shaped leaf

A single ginkgo tree can live to be 3,000 years old

While there are several varieties, it is the only tree in its species

While it is the only tree in its species, its classification confounds botanists

Some botanists say that the ginkgo is a deciduous conifer -- a type of tree with needles and cones, but which also has leaves that drop in the fall. True deciduous conifers include several species of larches, bald cypresses, the Chinese swamp cypress, and the Pond Cypress, and the Dawn redwood. These are also really old species of trees.

Some botanists argue that ginkgos are not really conifers, and so therefore are not a decidous conifer. These botanists say the ginkgo is more closely related to cycads, which is another very old group of plants, of which only some 250 species survive. These live in tropical places and they have leaves that grow out in a radiating circle from the central branch. They look like palm trees.

Still other botanists say the ginkgo is neither a conifer nor a cycad, but completely its own thing.

Apparently, botanists have a lot more to figure out when it comes to the ginkgo.

The seeds are another really unusual thing about this tree. The female ginkgo produces a fruit, inside of which is a nut in a shell, and the nut is edible in small amounts. But I need to break down each of these elements bit by bit.

The items in these four bowls all come from the fruit. What they call "berries" is the fruit of the female ginkgo. Inside the fruit is the nut in a hard white shell, almost like a pistachio shell. Inside the shell is the nut, which is best roasted. Once that's done, peel the outer layer off the nut to get to the glistening, green nut meat. But don't eat too many of them, or you'll get a stomach ache.
(Photo from Hot Topix Suburban Foragers)

What the fruit looks like on the ginkgo branch. These look a little too yellow; might need some more time to ripen.
(Photo from Kennesaw State University)

The fruit looks like a small, yellow plum, but it stinks like crap. Literally. Some people say it smells like vomit. Others say it smells like sulfur. Still others say it smells like sour milk. Let's just say it reeks bad.

It stinks so bad, scientists can't figure out what animal would want to eat that fruit and thus disperse the seed. They speculate that maybe the animal that used to eat it has since died out and the tree has outlived its disperser. There are records that badgers used to eat them, but no current evidence of such today. But somehow the seeds are still getting dispersed.

It could be that humans are now the ginkgo's greatest disperser because we now depend on this tree like crazy. Since it will grow in spite of conditions that threaten other trees, and it has no pests and no diseases that go after it, it's become enormously common, especially in cities. Lots of cities have lined their streets with ginkgo trees.

A tree-lined street in Mie prefecture, Japan
(Photo from Wikimedia Commons)

But here again, we run into the stink problem. People find the stink of the fruit to be so disgusting, they've asked that the ginkgo trees be removed. In various cities like Easton, PA, and Bloomington, MN, and Lexington, KY, they've done just that.

They haven't removed all ginkgos, only the stinky females.

Catalpa Road in Lexington, KY lined with ginkgos. Why they didn't call it Ginkgo Road, I don't know.
(Photo from Panoramio)

But there's a small problem: it takes 30 years for a ginkgo to reach its reproductive years. And it is nearly impossible to tell whether a tree is male or female before that time. So the cities that are trying to get rid of the females aren't even sure they've got them all.

And then a funny thing happens. Very occasionally, about 1 out of 100 male ginkgos will mysteriously transform. It will become female and start producing the stinky fruit.

This thing is doggoned determined to reproduce. I can almost hear those those ginkgo trees giggling at us and saying, "Silly humans. We have lived on this planet for millions of years. It's going to take a helluva lot more than you puny humans digging up a few of our females to wipe us out."

But even that is not all there is to say about the stinky fruits. They have the same toxin as poison ivy or poison oak. So if you want to harvest them for the nut inside, you'd better wear rubber gloves.

Also, the fruit contains a tannin which will stain your clothes or your shoes. One guy who lives on a street in Pennsylvania lined with ginkgos had to get his car re-painted twice because of the ginkgo stains.

Oh, and one more thing. People say the nut, when roasted, tastes like a cross between edamame, a pine nut, and a potato. Quite tasty, in other words. In various countries in Asia, the nut is considered a delicacy and is sprinkled on desserts, or in soups, or served with meats. Only problem is, the nut carries another kind of toxin which will make you throw up if you eat too much of it.

I can practically hear all the laughter from the ginkgos up and down this tunnel of them, in a park outside Tokyo.
(Photo from Maxi's Comments)

About the name.

The tree is native to China, and then it was brought to Japan. Its name is an Anglicized rendering of the Japanese version of the Chinese name yin-hing, where yin = silver and hing = apricot.

The tree was brought to Europe by a Dutch surgeon in 1727, and then to what is now the US -- Philadelphia, actually -- by William Hamilton in 1784. A few years later, he suggested to Thomas Jefferson that he might like three of them in his gardens at Monticello.

So the tree is pretty cool. But I can't talk about the tree without mentioning the supplements.

There are all sorts of claims out there about the health benefits of the ginkgo. In China, they say it's the seeds that have the health benefits. In the US, it's the leaves. Either way, such claims include but are not limited to the enormous list below.

The 3 with the asterisk are ones where there has been some good scientific evidence that may suggest some positive result. The rest are pretty much fluff.

Brain / Memory

Improves memory
Improves brain health
Reduces severity of migraines
Reduces symptoms of dementia*
Reduces effects of aging

Other Mental health

Benefits people with ADHD
Benefits people with autism
Benefits people with generalized anxiety disorder *
Benefits people with schizophrenia *

Respiratory

May reduce asthma symptoms
Treats scar tissue on lungs

Circulatory / cardiovascular

Improves blood circulation
Helps reduce high blood sugar
Helps in recovery from strokes
Reduces the number of attacks associated with Reynaud's disease (blood circulation)

Diabetes or related

Benefits people with retinopathy (diabetes-related eye damage)
Benefits people with kidney dysfunction, especially for diabetics

Eyes

Improves eye health and vision
Treats eye allergies

Ears / Balance

Treats chronic ear disorders
Aids in treating tinnitus
Treats altitude sickness
Reduces vertigo

Cancer

Prevents cancer
Shrinks stomach cancer tumors
Reduces effects of chemotherapy

Musculoskeletal

Improves performance in athletics
Assists in treating multiple sclerosis
Improves quality of life for people with fibromyalgia

Other

Reduces cocaine dependence
Treats erectile dysfunction
Reduces toxicity of radioactive iodine used to treat thyroid disorders
Treats hemorrhoids
Reduces symptoms of PMS
Gel form reduces wrinkles

Boy, one plant that can do all of that, treat everything from headaches to old age to wrinkles and schizophrenia and cancer? That sure must be some wonder drug!

(^sarcasm)

Shelf after shelf of dietary supplements, or herbal supplements, or natural supplements. This is code for "bullshit."
(Photo from Fake Food Watch)

One trial that asked people to take ginkgo supplements could not prove anything because they didn't get enough data. This is because the "natural" supplements that people were taking turned out to have less than the required minimum 24% ginkgo extract. The pills didn't have enough ginkgo in them to have an effect. Those "natural supplements" were, in effect, snake oil.

In general, any time somebody starts making claims like "X Natural Product is really good at treating Y Disease that traditional medicine is flummoxed by," don't fall for it. (See this article, one among thousands, on the problem with herbal supplements.) (Here's another one about the junk they found in generic herbal supplements, instead of what was supposed to be in there.)

If traditional medicine is stumped, do you really think some nutjob with a pile of ginkgo pills is going to know something they don't? Don't let them suck the money out of you. Smile and nod, and keep on walking.

You know who's getting the last laugh, don't you? The ginkgo trees. They're like, look at those idiots. Thinking my nuts are doing all kinds of wonderful things for them. All they're doing is dispersing my seeds. Disperse on, humans, disperse on.