In 1989, at Yima Formation, Yima, Henan Province, China, a team of paleontologists led by Zhiyan Zhou and Bole Zhang unearthed ginkgo fossils that they later dated to 170 million years—the oldest ginkgo fossils found. Other fossil discoveries in Europe, South Africa, Australia, and North America reveal that ginkgos once flourished on our planet.
Following the Cretaceous–Paleogene mass extinction 65 million years ago, the Quaternary brought periodic glaciation that swept across the planet, the last glaciation beginning some 2 million years ago. As a result, only a few plants, including one species of ginkgo trees, survived the catastrophes. These ginkgos found shelter in deep valleys of high mountain ranges in Central China.
Today, Ginkgo biloba trees represent the only genus of the family Ginkgoaceae of the order Ginkgoales of gymnosperms.
The special smell of its ripe seeds attracts animals including the Masked Palm Civet Paguma larvata, which eat them and disperse the hard-shelled nuts within their droppings. As animal-dispersed seeds, ginkgos spread in the wild. Ancient Chinese found ginkgo nuts tasty and planted them nationwide. Sometimes ginkgo seedlings were included among dowries of brides.
Because of their straight trunks and extraordinary shapes, ginkgos were often planted in front of temples, lending an atmosphere of awe and solemnity. Old Buddhist monks liked to use walking sticks made of ginkgo stems. When they traveled as missionaries, they stuck their sticks at temple courtyards and new trees grew. This practice spread ginkgos to the Korean peninsula and Japan in the fifth century.
Engelbert Kaempfer, a German botanist and physician of the Dutch East India Company, discovered the ginkgo while stationed in Japan during the 1730s. He sent the seeds to Holland, and the first ginkgo tree in Europe grew at the Botanical Garden in Utrecht. In 2001, this oldest ginkgo tree in the West was 1.32 metres wide in diameter at breast height. From Holland, ginkgos were introduced to other European countries and to North America. In 1784, a ginkgo was planted in William Hamilton’s garden in Philadelphia, U.S.A.
Ginkgo is a dioecious plant. Males and females are separate trees. How to tell male from female?
In spring, male ginkgos tend to germinate earlier. They grow pollen. Their leaves are more divided, and in autumn they fall later. Meanwhile, female ginkgos tend to germinate later. They grow ovules. Their leaves have no split and fall earlier in autumn.
Check the angle between trunk and branches: branches of males tend to be more erect, about 30 degrees between; those of females more horizontal, about 50 degrees between, for females to grow seeds and to get sufficient sunlight.
The ginkgo ebook is out. Learn a lot of stories by a native photographer stationed in the world only wild ginkgo forest in East China.