City folks, especially in New York and Philadelphia are quite familiar with ginkgo trees, not only because of their exotic fan-shaped leaves and the stinky fruits they drop in late summer, but also due to their ubiquitous presence up and down hundreds of city blocks, spreading cooling shade in older neighborhoods.
Ginkgo (ginkgo biloba), also known as the Maidenhair Tree, is one of the oldest living trees in the world, originating in China and dating back nearly 290 million years. It is truly unique, being a single species that has no living relatives. We know dinosaurs and ginkgo trees existed together because we have fossils to prove it. Dinosaurs loved the malodorous fruits and gorged on them, the undigested seeds helping to expand the range of the trees throughout the prehistoric world.
But then an ice age chilled the planet 66 million years ago and the dinosaurs disappeared, along with most all other known animal and plant species of the time. Except for the ginkgo trees. They are natural survivors.
Ginkgos today look exactly the same as their fossils from 200 million years ago, hence their nickname as “living fossils.”
Among the ginkgo tree’s superpowers: their leaves are unpalatable to all insects and their bark secretes a sap that makes them fire-retardant. The species can also easily withstand drought, storms, snow and freezing ice (obviously!), salt, hard-packed city soils, and pollution. In fact, six ginkgo trees are even known to have survived the atomic bomb and are still growing in Hiroshima, Japan.
Even more unusual is the fact that ginkgo trees tend to drop all or most of their leaves in one night. The first hard frost of the season sends a signal to the stems of the leaves to release the leaves simultaneously. By morning, confetti-like piles of golden leaves encircle the base of each tree.
Ginkgo trees are slow growing, but eventually can reach heights of 150-170 feet. And due to their incredible hardiness, they are also exceptionally long-lived. Individual trees have been known to last for up to 3,000 years. Currently, the oldest living ginkgo tree is located within the walls of the Gu Guanyin Buddhist Temple, in the Zhongnan Mountain region of China. It is 1,400 years old.
It comes as no surprise then that among the many traditional health remedies made from ginkgo leaves and seeds, a medicine derived from the ancient tree’s leaves is used for treating age-related dementia.
Photo: This massive ginkgo tree that looms over Broadway at Isham Street in New York City is thought to be about 170 years old. (Author photo).