Ginkgo – Ginkgo biloba
Our Ginkgo tree with its narrow pyramidal form stands like a sentry at the at the edge of Bayne Park near the Skate Plaza. The upward angled branches are engulfed by an abundance of foliage.
Ginkgo trees are one of the oldest living tree species dating back to over 150 million years. You may have noticed a Ginkgo tree near the Camptosaurus in the Dinosaurs in their Time exhibition at the Carnegie Museum of Natural History, because dinosaurs lived alongside Ginkgo trees!
Ginkgo trees are sometimes called Maidenhair trees due to the similarity of the leaf to maidenhair fern leaflets shown in the above image on the right.
The elegant fan-shaped leaves appear in clusters held close to the branch. They feel waxy and have long flexible petioles which allow the them to flutter in even the slightest breeze. Meaning two lobes, the Latin species name ‘biloba’ refers to the leaf shape which is sometimes entire, but typically has a cleft in the middle creating two lobes.
Look closely at the image above to see the radiating venation on the leaf. The thin veins branch outward from the stem repeatedly diverging into two, until they ultimately terminate at the wide ruffled edge.
The columnar trunk features grey-brown ridged bark with fissures.
Ginkgo trees are dioecious, which means each tree is either male or female. The reproductive structures of the Ginkgo are not considered flowers.
Ginkgo leaves and the tree’s reproductive structures emerge from woody spur shoots which consist of a series of stacked leaf scars.
After successive stacking over the years, the longer spur shoots can be mistaken for thick thorns when observed from the ground looking up into the canopy.
The female reproductive structures are called ovules. In early Spring as leaves are emerging, the female trees grow slender stalks which support paired ovules that appear as green tiny pointed orbs. The ovules secrete a mucilaginous pollen droplet which increases the likelihood that windswept pollen from male trees will reach its target.
Male trees produce pendulous pollen-bearing reproductive structures called strobili that grow from the spur shoots beneath the leaves. They become yellowish when laden with pollen.
Our Ginkgo tree in Bayne Park is a female tree as evidenced by the the prolific layer of fleshy covered seeds found on the ground beneath the tree.
Typically dropping before the leaves fall, the fleshy part splits open and begins to decay, emitting a strong putrid odor due to the chemical compound butyric acid. The foul smell may attract carnivores like coyotes and badgers by mimicking the scent of rotting flesh. Animal consume and transport the seeds, dispersing them elsewhere in their scat.
Ginkgo trees can have impressively long lifespans. This robust tree is rarely affected by insects and disease. It can endure pollution, confined soil space, extreme heat, and drought.
Although we are not advocating the consumption of any part of the tree, Ginkgoes have long been valued for their medicinal properties, and the roasted seeds and are considered a delicacy in some parts of the world. The lightweight brittle wood is occasionally used to create chess sets, and chopping blocks.
The leaves turn an astonishing vivid saffron-yellow color in Autumn.
Most deciduous trees gradually shed their leaves, but Ginkgo leaves tend to fall quickly, dramatically carpeting the ground beneath the tree.
Why would leaves of different tree species fall at different rates? Before dropping their leaves, deciduous trees form a protective scar between their leaves and stems. Most trees form the scars gradually as the temperature decreases, first forming scars at the most exposed exterior leaves. Once those leaves drop, more leaf scars are formed on other newly exposed portions of the tree. This sequential process causes the leaves to gradually drop over a longer period of time. Ginkgoes rapidly form the scars on all of the stems on the entire tree, and the first hard frost causes the leaves to abruptly drop to the ground together over a shorter period of time.
Pittsburgh’s largest known Ginkgo Biloba tree is located at Highland Park with a trunk circumference of roughly eighteen feet, branches spreading one-hundred-and-forty feet from one side to the other, and height over one-hundred feet tall.
For a spectacular display of golden Autumn foliage, visit Allegheny Commons Park in the Northside to take in the vista of rows of Ginkgo trees lining the railroad tracks by Lake Elizabeth.
Ginkgo: The Tree that Time Forgot by renowned Botanist Peter R. Crane is an engaging informative book that explores the history of Ginkgo trees and highlights their cultural and social significance.
The Overstory by Richard Powers is an impassioned novel about the value and wonder of trees. Olivia, a main character adopts the pseudonym “Maidenhair” when she joins an environmental group dedicated to the protection of trees.
The Happiest Tree: A Story of Growing Up by Hyeon-Ju Lee is narrated by a Ginkgo tree! It features expressive artwork and shares an emotional story of time passing.
Thank you for joining us and virtually meeting our Ginkgo tree at Bayne Park today. We hope this virtual experience helps you to feel connected to the trees, and we encourage you to visit all of the beautiful trees at Bayne Park.