Ginkgo leaves are shaped like unfolded folding fans. The ancients thought they were like webbed duck feet, so they were called duck foot trees. The name of Ginkgo comes from its orange seed coat covered with white powder, which makes the seeds look like apricots with silver frost. After removing the smelly fleshy exotesta, you can see its hard white mesotesta. Ginkgo seeds are also called ginkgo. Ginkgo grows slowly. Grandpa grows trees and can't eat ginkgo until his grandchildren. Therefore, it is also called Gongsun tree. Ginkgo has solid wood and can be grown for thousands of years.
Ginkgo biloba is called "living fossil" for many reasons.
First, ginkgo plants have changed very little since the Jurassic 200 million years ago. The fossils of ginkgo have appeared in the Middle Jurassic (about 170 million years ago). They were produced in Yima, Henan Province, China. From Yima Ginkgo biloba, Ginkgo biloba has presented staggered long and short branches, fan-shaped leaves and seeds with bead collar. From Yima Ginkgo biloba to living Ginkgo biloba, after 170 million years, they just have shallow leaves, few seeds and grow big. In other words, Ginkgo biloba has evolved very slowly since Jurassic.
Second, there is only one species of Ginkgo in the order of ginkgo, and there are more than 200 species of 10 genera in the order of pines and cypresses, which are gymnosperms. However, looking back, you will find that the hairy leaves, the oldest member of ginkgo, appeared in the early Permian 270 million years ago. The Late Triassic, 230 million years ago, was the golden age of Ginkgo biloba, which reached its peak from Jurassic to early Cretaceous. The ginkgo family, which includes more than 10 genera and dozens of species in 5 ~ 7 families, was one of the most important groups in the forest at that time. However, after the great decline of the late Cretaceous, there was only one gingko family left in the order of Ginkgo biloba, only one gingko genus left in the family of Ginkgo biloba, and there was only one species of Ginkgo biloba, which became the last survivor of the deceased family.
Third, the distribution area of the native population of the living Ginkgo biloba is very small, which is only distributed in Tianmu Mountain, Zhejiang, China. But in the age of dinosaurs, ginkgo and its relatives were found almost all over the world. The decline of Ginkgo plants began in the early Cretaceous 130 million years ago. With the rise of angiosperms, they retreated step by step. Until the late Cretaceous and early Cenozoic (90-55 million years ago), ginkgo was still distributed around the Arctic in Eurasia and high latitudes of North America; After Oligocene (34 million ~ 23 million years ago), it has been in the process of extinction; At the end of Miocene (about 10 million years ago), ginkgo withdrew from North American forests; It withdrew from Europe at the end of Pliocene (about 1.7 million years ago); Finally, only East Asia has traces of Ginkgo biloba.
However, although the current situation of the original population of Ginkgo seems precarious, ginkgo itself is not a fragile species. It has strong resistance and lives well wherever it is transplanted. Perhaps, after the exclusion of other plants and the baptism of the great ice age, the ginkgo in the "shelter" has become stronger and will survive tenaciously in this world.