Ginkgo leaves. The ginkgo (Ginkgo biloba) is a tree native to eastern Asia that has been introduced around the world. It has no living relatives, but fossils from as far back as the Permian period some 270 million years ago show that the tree has changed little in that time. As such, it is considered a living fossil. It is extremely resistant to disease and stress, and it is planted extensively in urban areas. Extracts from the leaves are used in herbal medicine, where they are said to enhance memory, boost energy levels, increase blood flow and protect against damage by free radicals.