Saturday, November 11, 2017

Ginkgo Day in the Time of Thanksgiving

First, a little history: The Ginkgo tree is native to China and has been widely cultivated. It has resisted evolutionary change for approximately 270 million years. That’s why it is considered a “living fossil.” There are male and female Ginkgo trees (dioecious), with the female producing a fruit that smells horrible when it falls and decomposes. The leaves of these trees are fan shaped, a very distinctive appearance often reproduced by artists as design elements of all kinds. Each autumn, the Ginkgo is known to shed all of its leaves within a period of several hours on a day in late October or November, depending on location and weather.

We had a male Ginkgo in the back yard of our last home. We called the annual leaf drop, “Ginkgo Day.”

Gingko With Leaves
Gingko After Leaf Drop
I’m not sure what year we first noticed the Autumn behavior of our little tree. I distinctly remember looking out a window that faced our back yard one windless November morning and seeing its bright yellow leaves falling like rain, covering the ground around the trunk with multiple layers, like a heavy golden snow. By the time I got home from work that day the tree was completely bare, not a leaf left on any branch. I have included a short video here of a less spectacular leaf drop, but one that yielded the same results in 2015.

I began tracking the date of Ginkgo Day on our calendar. In Lincolnshire, Illinois the date ranged from November 8th to the 27th over a period of about ten years. One year a particularly severe and early hard freeze caused the leaves to drop while still green in color, but still within the confines of a work day. Ginkgo Day was not ruined, it was just different that year.

It got to the point that I started an office pool, offering a prize for the person who correctly guessed the date of the leaf drop. As I recall, no one guessed the exact date, but someone came close. I posed the same challenge on Facebook, with similar results.

In 2012, Ryerson Nature Center near our home hosted a lecturing botanist by the name of Peter Crane. Sir Peter Crane, mind you, knighted in 2004 and a member of the Royal Society in London. I’m not sure why he became so distinguished, but the dude had his Ginkgo on, and sold copies of his book Ginkgo, The Tree That Time Forgot, which he dutifully autographed for me.

During the question portion of his lecture, I commented on what I’d observed, and that I’d made a game of it. Was this just our tree, or a known characteristic of the genus? He smiled as I described the office pool and commented that the University of Wisconsin at Madison had done something similar. Yes, it was a known quality.

Linnaeus may have named and described the Ginkgo in 1771, but others like myself, in our admiration for our beloved Ginkgo later documented this behavior.

We have since moved to Florida and left our special tree behind under the care of strangers who may or may not be aware what a unique specimen they have on their property. As much as I would love to grow a Ginkgo at our new home, from what I’ve read it will not survive in this climate. So while we no longer have an object of our singular focus, we’ll amuse ourselves with the variety and splendor of the local flora. I’ve often commented that we now live in Jurassic Park. The Ginkgo and alligators have that much in common.

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