Due to their incredibly long history (ginkgoes are hundreds of millions of years old, and fossils have been found from the Middle Jurassic Period), they have seen considerable changes in habitat. They were once widespread, but about two million years ago their habitat shrunk and current ginkgoes trace their ancestry back to China. They were preserved in temples in China and Japan (there is some debate as to whether any of the present-day wild trees are not descendants from these temples), but currently enjoy worldwide distribution due to their hardiness and medicinal uses.
Origin, history, and uses:
As stated before, ginkgoes existed during the Middle Jurassic Period, meaning they predated the Torosaurus that has a statue in the Cretaceous Garden, the Tyrannosaurus Rex, and the Triceratops. They were a very successful group of plants for millions of years, but experienced a significant shrinking of habitat about two million years ago. Ginkgoes are thought to be alive today because of their involvement in the lore of the Far East; Confucius was said to have done his teaching under the shade of a ginkgo tree. For this reason, ginkgoes were preserved in temples throughout China, and gradually reintroduced as it gained recognition for its medicinal properties.
Ginkgo products were used for centuries in Chinese traditional medicine. Today, compounds from the tree are also used in commercial medicines for cognitive complaints such as Alzheimer’s. For this reason, ginkgo trees once again enjoy a worldwide distribution.
Ginkgoes are very hardy trees, which allows them to have a wide habitat range. For this reason, ginkgo trees can have widely varying phenology; trees in China can have vegetative growing seasons ranging from 170 days to 260 days depending on their latitude. If winters are mild, trees can begin pollination as early as mid-March, while long winters can make the trees pollinate as late as the beginning of May. Fertilization occurs about 130 days after pollination, meaning a range of August through October. Fertilized ovules mature in the fall, and turn yellow along with the leaves. They eventually drop when temperatures near freezing, which is again climate-dependent. Finally, germination depends on outside temperature, with seeds in warm greenhouses beginning to sprout as early as 6 weeks after falling while seeds outside in cold climates, such as Boston, may take over a year to begin the germination process.
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