Ginkgo biloba

Ginkgo, also known as the Maidenhair Tree after Adiantum, is a unique species of tree with no close living relatives. The ginkgo is classified in its own division, the Ginkgophyta, comprising the single class Ginkgoopsida, order Ginkgoales, family Ginkgoaceae, genus Ginkgo and is the only extant species within this group. It is one of the best-known examples of a living fossil, because Ginkgoales other than G. biloba are not known from the fossil record after the Pliocene. For centuries it was thought to be extinct in the wild, but is now known to grow in at least two small areas in Zhejiang province in Eastern China, in the Tian Mu Shan Reserve. However, recent studies indicate high genetic uniformity among ginkgo trees from these areas, arguing against a natural origin of these populations and suggesting that the ginkgo trees in these areas may have been planted and preserved by Chinese monks over a period of about 1000 years. Whether native ginkgo populations still exist has not been demonstrated unequivocally. The relationship of Ginkgo to other plant groups remains uncertain.