Ginkgo biloba is the strangest tree I know. It’s a conifer, sort of, but with deciduous leaves. Its leaves are neither pinnately- nor palmately-veined. It’s the only living member of its genus and family, and the genus (Ginkgo) dates back 270 million years, the species (biloba) 51 my. Fossilized Ginkgo leaves are found on every continent, including Antarctica. And male trees produce motile sperm!
Ginkgo is both the Latin name and the common name of the tree, and because Ginkgo biloba is the only living species of Ginkgo, I’ll simply use its common name, “Ginkgo”. The common name, “Ginkgo” is occasionally spelled with the g before the k, but since the Latin name is “Ginkgo”, I put the k first. [There’s a discussion of Latin names at the end of this article].
Ginkgo Leaves and Branches
Ginkgo leaves and branches are alternately-arranged, i.e., they are not attached directly across from one another. However, they often occur in clusters at the end of a shoot. They are also simple, and do not share a stem with other leaflets in groups of 3, 5, 7, etc., as is the case with compound leaves.
The fan-shaped leaves are 1 to 2 inches wide, and 1.5 to 3 inches long. They have no teeth. Ginkgo leaves often have two lobes, with a split down the middle, hence the name, Ginkgo biloba. Most deciduous tree leaves are either pinnately-veined or palmately-veined. Pinnately-veined (feather-like) leaves have a primary vein running along the leaf’s length, and secondary veins attached to it at various points. Palmately-veined (hand-like) leaves have multiple large veins attached at the base, and secondary veins attached to them. But Ginkgo leaves have neither pattern. The veins on Ginkgo leaves fan out in a more-or-less parallel pattern, with veins splitting to produce two more parallel veins, in a pattern known as “dichotomous venation”.
Leaves grow from bumps on the limbs known as “spur shoots” or “short shoots”. Spur shoots grow slowly, so the leaves tend to be clustered in groups at the shoots’ ends. These shoots are especially obvious in winter after the leaves have fallen, and make Ginkgo recognizable at a glance. In between short shoots are slender twigs known as “long shoots”, which can grow over a foot in length each year. Ginkgo leaves are known for their beautiful golden fall color, and they tend to drop from the tree in a matter of one or two days.
Ginkgo Cones and Fruit
Conifers produce cones, while non-conifers produce fruits, and the difference is usually obvious. But the cones of some conifers, such as Eastern Redcedar, look more like berries than pine or spruce cones. The difference is non-conifers (aka angiosperms – “vessel-seeds”) produce fruits inside an ovary, and conifers (gymnosperms – “naked seeds”) do not. Ginkgo’s seeds don’t develop in an ovary, and so Ginkgoes are classified as gymnosperms, as are conifers. Ginkgo’s seed-bodies aren’t strictly cones, either, so you’ll see the terms ‘fruit’, ‘cone’, and ‘“cone”’. Whatever. I’ll call them “cones”.
Ginkgoes are dioecious. meaning that they have separate male and female trees, whereas monoecious trees produce pollen and flowers on the same tree. Female Ginkgoes produce cones that resemble apricots. Males produce pollen that is carried by wind for most of its journey. But the final distance is covered by sperm with multiple flagellae – a trait Ginkgo shares with cycads, ferns, mosses, and algae. The ability of Ginkgo pollen to find its way on the home stretch means that less of it is needed than for plants that are entirely wind-pollinated.
The resulting apricot-like fruits don’t smell like apricots, because they contain butyric acid, which smells like a mixture of dog droppings and vomit. Consequently, most of the Ginkgo biloba trees sold at nurseries are males. The cones contain a single seed, covered with a woody shell, about the size of a sunflower seed. The seeds smell and taste okay, and are regarded as a delicacy in Asian cuisine, but they can harm your health if eaten in quantity. Ginkgoes are reportedly easy to grow from seed, and on occasion, they produce aerial roots from their branches that take root and turn into new trees. The USDA Woody Plant Seed Manual indicates that Ginkgo trees begin to bear seeds at the age of 30 to 40 years.
Ginkgo Bark
Ginkgo bark is somewhat light gray, moderately deeply furrowed, with rounded ridges. Ginkgoes are among the trees that can often be recognized by their bark, but its character is not obvious in photographs. It’s good practice to note a tree’s bark, shape, and other permanent features in the summer when the trees are easily identified, so that for reference in winter when the leaves are gone.
Mature ginkgoes typically have a height of 50 to 70 feet and a trunk diameter of approximately 2 feet. Ohio’s Champion, located in Hamilton County, has a height of 97 feet, a trunk diameter of 6.8 feet, and a crown width of 105 feet. Ginkgoes can live for several thousand years, and in the process, might reach heights of 120 feet or more.
Ginkgo Identification Summary
ID Summary: Fan-shaped leaves with parallel veins, with yellow fall color. Foul-smelling apricot-like fruits on females. Distinct, stubby spur shoots on branches in winter.
Similar Trees: Unlikely to be confused with other trees.
Ginkgoes grow well in both moderately alkaline to moderately acidic soil, ranging from pH 5.0 to 8.0. They prefer moist, well-drained soil. Ginkgoes tolerate soil compaction and pollution, making them popular in landscaping, and they prefer full sun. They’re disease-resistant, long-lived, and their branch structure and deep roots make Ginkgoes wind- and snow-resistant. And finally, they’re said to be easy to propagate from seed. But despite their hardiness, Ginkgoes are not invasive, at least in Ohio, and they’re limited to landscaping.
The Columbus, Ohio Street Tree Inventory ranks Ginkgo as the City’s 26th most common street tree, at just over 1% of the total trees. As a native of China, there are no range maps showing the native location of Ginkgoes in the U.S.
Ginkgo Wood and Seeds
Ginkgo biloba wood has a Janka hardness of 750 lbf and a density of 0.46 g/cc, according to the Wood Database, compared to the median of my list of 73 Ohio trees of 1,075 lbf and 0.64 g/cc. Ginkgo is normally not a lumber species in the U.S., but it is used in Asian countries. The wood is light brown to white, straight-grained, and relatively soft. It stains, finishes, and works well. The wood is speculated to be rot-resistant, but it’s unclear if the living tree’s resistance to insects in life translates to resistant lumber. In Asia, the wood is used for carvings, chess boards, small furniture, and casks for making saké. Ginkgo wood is very stable, with minimal shrinkage and warpage, making it the ideal substrate for lacquerware.
Ginkgo seeds are edible and they’re popular in Asia, but they contain ginkgotoxin, which can cause health problems, including convulsions, if consumed over long periods. Some people are allergic to the fruits, and contract dermatitis, similar to that from poison ivy. Ginkgo can also potentially cause cancer. But the dose makes the poison, and Ginkgo biloba is also touted for its medicinal properties, especially for treating or preventing dementia. Ginkgo has not been approved for dementia by the U.S. Food and Drug Administration, but it has been approved by the European Union. Ginkgo seeds and leaves have been used in Chinese medicine for centuries to treat dementia, respiratory ailments, and urinary disorders.
Medicinal Uses
The Peterson Field Guide to Medicinal Plants and Herbs of Eastern and Central North America lists the following medicinal uses for Ginkgo biloba:
- Traditional Chinese Medicine to treat lung ailments. Externally, as a wash for skin sores and to remove freckles,
- Clinically (though controversial) shown to improve short-term memory attention span, and mood in earlv stages of Alzheimer’s, and
- Extract approved (in Germany) for memory and for vertigo and ringing in the ears (tinnitus) caused by vascular disturbances.
The Tree Spirit Wisdom website indicates that Ginkgoes were planted near Taoist and Buddhist temples as symbols of yin-yang – darkness and light. Yin is also seen as the feminine essence of earth, and yang as the masculine essence of the sun.
According to Alice Thoms Vitale’s Leaves In Myth, Magic, & Medicine, the Chinese and Japanese believe that Ginkgo leaves are not only disease-resistant, but also fire-resistant. The belief stems from a fire that destroyed much of Tokyo in 1923, but spared a particular temple that was surrounded by Ginkgoes.
S. Theresa Dietz, in The Complete Language of Trees, informs us that Ginkgoes have the possible powers of an aphrodisiac, they enhance fertility and healing, and they improve longevity. And, of course, Ginkgoes provide oxygen.
Ginkgo is an ancient and intriguing tree that’s easy to recognize, and admire, any time of year.
About Latin Names
Latin genus and species names take time to learn, but they have the advantage of being more consistent than common names. For example, Ohio’s American Hornbeam (Carpinus caroliniana) also goes by the common names “Muscle Wood”, “Blue Beech”, “Ironwood”, and “Leverwood”, among others. Unfortunately, “Ironwood” is also used to describe another Ohio tree, the Eastern Hop Hornbeam (Ostrya virginiana), and more than 100 other species, worldwide, that happen to have very hard wood. The Latin name, “Carpinus caroliniana” eliminates any confusion. Latin names change occasionally for various reasons, but there are far fewer of them than common names, and they’re the same in publications printed in English, German, Spanish, etc.
The standard for Latin names is to state the genus, followed by species. For example, Quercus macrocarpa (Bur Oak), means “oak with large fruit”, and Q. alba means “oak, white”. The genus is a noun, capitalized, followed by the species, an adjective, in lower case. The genus and species are normally italicized, (or underlined in the days of typewriters, when fonts were generally fixed). If species of the same genus are discussed in close proximity, the genus name can be abbreviated with the first letter, e.g., “Quercus macrocarpa and Q. alba”. (By the way, “species” is both singular and plural. “Specie” is money in the form of coins).
Latin names are far easier when researching plants or animals. When looking for American Hornbeam in a book’s index, do you look for “Ironwood”, “American Hornbeam”, “Hornbeam, American”, “Musclewood”, “Blue Beech”, or “Leverwood”? “Carpinus caroliniana” will get you there much faster.
And finally, common names may or may not be capitalized. More often they aren’t. But I prefer to capitalize the common names of species, e.g., “Bur Oak”, but not the names of broader categories, such as “oaks” or “maples”.
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You can also listen to my talks on Ohio Broadleaf Tree Identification on YouTube, Part 1 and Part 2.
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