A ginkgo is a large, deciduous tree with distinctive fan-shaped leaves that belongs to one of the oldest lineages of living plants. It is the sole surviving species from a group of ancient trees believed to have existed up to 150 million years ago, earning it the nickname “living fossil.” Native to China, ginkgo is now planted worldwide as an ornamental shade tree and is widely used in herbal supplements.
What Makes Ginkgo Unique
The ginkgo (scientific name Ginkgo biloba) stands alone in the plant kingdom. It is the only living member of its entire botanical division, meaning it has no close relatives among modern trees. To put that in perspective, it would be like a single species being the last representative of all mammals. Fossil records show ginkgo-like plants spread across multiple continents during the age of dinosaurs, but every related species eventually went extinct.
Its leaves are easy to recognize: leathery, fan-shaped, and split into two lobes with veins that run nearly parallel from stem to edge. In autumn, the foliage turns a bright golden yellow before dropping. Mature trees can reach 80 feet or taller, with a broad canopy that makes them popular along city streets and in parks. Ginkgo trees are also remarkably tough, tolerating pollution, compacted soil, and drought better than most urban species.
Male and Female Trees
Ginkgo trees come in separate male and female forms, a trait botanists call dioecious. You won’t know which you have until the tree is mature enough to reproduce, which can take 20 years or more. The distinction matters because female trees produce fleshy, fruit-like seed coverings that emit a notoriously foul smell, often compared to rancid butter or vomit. For this reason, most cities and nurseries plant only male trees.
Research on ginkgo seedlings shows measurable differences between the sexes even at a young age. Male seedlings grow taller, develop thicker stems, and photosynthesize at a higher rate than females. Female trees, on the other hand, produce higher concentrations of the plant’s signature medicinal compounds, including flavonoids and terpene lactones. These chemical differences are one reason researchers have worked to develop genetic tests that can identify a tree’s sex before it reaches maturity.
The “Living Fossil” Label
Charles Darwin popularized the term “living fossil,” and ginkgo is one of the most cited examples. A 2019 genomic study published in Nature Communications resequenced 545 ginkgo genomes from populations around the world. The data revealed a complex demographic history stretching back at least 20 million years, with populations expanding and contracting through multiple ice ages. Despite all that time and upheaval, the tree’s physical form has barely changed from its fossilized ancestors.
One surprising finding from the genetic data: ginkgo retains substantial genetic diversity despite its ancient lineage and near-extinction. Many scientists had assumed that living fossils were evolutionary dead ends with little genetic variation, but ginkgo’s genome tells a different story. Its survival appears to owe a great deal to human cultivation. Chinese monks and gardeners maintained ginkgo trees at temples for centuries, likely rescuing the species from disappearing entirely in the wild.
Ginkgo as an Herbal Supplement
Ginkgo leaf extract is one of the most widely sold herbal supplements in the world, primarily marketed for brain health and circulation. The two active ingredient groups are flavonoid glycosides (a class of antioxidants) and terpene lactones (compounds that include ginkgolides). Standardized extracts typically contain 24% flavonoids and 6% terpenoids.
The evidence for cognitive benefits is modest. A quantitative analysis of clinical trials involving people with Alzheimer’s disease found a small but statistically significant improvement in cognitive test scores after three to six months of taking 120 to 240 mg of standardized extract daily. The effect translated to roughly a 3% improvement on a standard cognitive assessment scale. That’s measurable in a study but subtle enough that a person might not notice a dramatic change in everyday life.
Ginkgo also appears to improve blood flow. In a study of healthy older adults, ginkgo extract increased coronary blood flow by about 19% and improved the ability of blood vessels to relax and widen by 56% compared to baseline. This vasodilatory effect is the basis for its traditional use in supporting circulation, particularly to the extremities and brain.
Safety Concerns and Seed Toxicity
Ginkgo leaf supplements are generally well tolerated, but they carry a meaningful interaction risk with blood-thinning medications. The terpene lactones in ginkgo act as potent blockers of platelet-activating factor, which reduces the blood’s ability to clot. A systematic review of 18 randomized controlled trials found that ginkgo significantly reduces blood viscosity. If you take anticoagulants or antiplatelet drugs, combining them with ginkgo raises the risk of bleeding.
The seeds pose a separate and more serious hazard. Raw or undercooked ginkgo seeds contain a neurotoxic compound called ginkgotoxin that interferes with vitamin B6 metabolism in the brain. Poisoning symptoms include vomiting, seizures (both tonic and clonic), and loss of consciousness. Ginkgo seeds are eaten in some East Asian cuisines, but they are always cooked and consumed in small quantities. The toxin in ginkgo seeds is unrelated to the leaf extracts sold as supplements.
Why Ginkgo Trees Are Everywhere
Cities around the world plant ginkgo for practical reasons. The trees resist insect damage, tolerate air pollution, and rarely suffer from serious disease. Their root systems handle sidewalk and road conditions better than many alternatives. In autumn, ginkgo trees drop all their leaves within a very short window, sometimes just a day or two, which makes cleanup easier than trees that shed gradually over weeks.
Several ginkgo trees famously survived the atomic bombing of Hiroshima in 1945, resprouting from charred trunks the following spring. These trees are still alive today, standing as a quiet testament to the resilience of a species that has outlasted nearly everything else on Earth.