The species known scientifically as Ginkgo biloba is often referred to by the common name, the Maidenhair Tree. This designation stems from the unique architecture of its fan-shaped, deeply cleft leaves, which closely resemble the fronds of the delicate maidenhair fern. As the only surviving member of its taxonomic order, the tree holds a distinctive place in the botanical world due to its unparalleled evolutionary history. Native to East Asia, this tree is widely cultivated and admired for its unusual foliage and robust nature across the globe.
An Ancient Survivor
The Ginkgo is frequently described as a “living fossil,” a term that speaks to its astonishing evolutionary persistence over immense spans of time. Fossils recognizably related to the modern species date back to the early Permian period, approximately 290 million years ago, making the Ginkgoales order older than most dinosaurs. This single species is the final remaining representative of a lineage that once diversified and flourished across the supercontinent of Laurasia during the Jurassic and Cretaceous periods. While most of its relatives disappeared from the fossil record by the end of the Pliocene, Ginkgo biloba persisted in refugia in China. Its survival through multiple major extinction events and severe climatic shifts highlights its extraordinary genetic resilience.
The Biology of Separate Sexes
The reproductive life of the Ginkgo is defined by dioecy, meaning individual trees are strictly either male or female. Male trees produce small, stalked pollen cones that release airborne pollen, while female trees produce ovules that, once fertilized, develop into seeds.
The reproductive structures on the female tree are technically not true fruits, as the Ginkgo is a gymnosperm related to conifers, not a flowering plant. Instead, the female tree develops a seed encased in a fleshy outer layer, called the sarcotesta, which resembles a small, yellowish apricot. This sarcotesta is the source of the tree’s most notorious biological feature—a strong, unpleasant odor released when the seeds ripen and fall.
The distinctive smell is caused by the presence of butyric acid, a compound also found in rancid butter, which makes the ripe seeds highly undesirable in urban settings. Because of this foul odor, city planners and commercial nurseries overwhelmingly favor planting male cultivars, such as the popular ‘Autumn Gold,’ to avoid the cleanup and smell associated with the female trees.
Ginkgo in Human Health
The leaves of the Ginkgo have a long history of use in traditional Eastern medicine, particularly in China, where they were employed for treating respiratory ailments and improving blood flow. This ancient application has transitioned into its modern use as one of the most widely consumed herbal supplements in the Western world. Modern extracts are standardized, focusing on compounds concentrated in the fan-shaped leaves, not the seeds.
The primary active components in the standardized leaf extract, often designated as EGb 761, are potent antioxidants, including flavonoids and terpenoids like ginkgolides. These compounds are believed to exert their effect through enhancing microcirculation by dilating blood vessels and reducing oxidative stress in the brain. The supplement is commonly marketed for its potential to support cognitive function, memory, and concentration.
Contemporary scientific research presents a balanced picture regarding the extract’s efficacy. Some clinical trials show benefits, particularly for individuals with mild cognitive impairment or early-stage dementia. Studies suggest that long-term administration, often at a daily dosage of 240 mg, may improve certain cognitive and functional capabilities in this population. However, results regarding cognitive enhancement in healthy, younger adults have been inconsistent, indicating that the most notable effects appear to be in individuals experiencing age-related decline.