Ginkgo is the world's oldest living tree species, also known as the maidenhair tree. The ginkgo tree grows to a height of 125 feet and bears fan-shaped leaves. In China, it was cultivated as a sacred tree, and is still used as an ornamental to beautify Buddhist temples.
Male trees are the preferred ornamentals.
The leaves are then extracted with an acetone-water mixture. The extract is processed, dried, and standardized to a potency of 24 percent flavonoids and 6 percent terpenes. American clinical study was published in 1997. In a significant number of the patients, ginkgo improved cognitive performance and social functioning. It is on the basis of this study that claims are made as to its effectiveness as an herbal supplement.