Autumn foliage turn from green to gold, saffron to rust
Ginkgo biloba, a hardy tree commonly found along city streets, is considered a “living fossil.” It is closely related to prehistoric ancestors, but has no relatives today. Dr. Scott Wing, a Smithsonian paleontologist featured in the conference, has been studying fossils of gingko leaves from a time of sudden greenhouse warming 55 million years ago. By counting microscopic pores on the leaves, he and other scientists have estimated the amount of carbon dioxide in the prehistoric atmosphere. By comparing the pores to those on living ginkgo leaves, they have been able to compare the prehistoric atmosphere to our own. The ginkgo, native to China, figures prominently in Asian art as well as the Art Nouveau movement of the late nineteenth century, two fields of interest for the Smithsonian’s Sackler and Freer galleries. Ancient Chinese artists often depicted the Buddha’s Dragon Tree as a ginkgo. Chinese monks brought the ginkgo to Japan, where it was widely planted in temple gardens. In Japanese decorative art, the ginkgo’s distinctive fan-shaped leaf has carried symbolism along with its singular beauty: the ginkgo has been a symbol of longevity (the tree can live for a thousand years) and of a more profound endurance (four ginkgos survived the blast at Hiroshima and are still growing today). In the mid-nineteenth century, the opening of Japan to western trade set off a craze for “all one sees that’s Japanese,” as a rhyme by W. S. Gilbert puts it—a craze both spoofed and exemplified in Gilbert and Sullivan’s The Mikado. Japanese decorative ideas, including ginkgo-leaf patterns, were later adopted by artists and architects working in the Art Nouveau style, a forerunner of Art Deco. Art historian Paul Johnson defined Art Nouveau as an attempt “to soften the implacable advance of machinery by giving it, whenever possible, organic forms which expressed the eternal growth-cycle of nature.” The concern of those artists is recognizable to us today: the balance between nature and progress, between the world we’ve inherited and the world we make for ourselves. It is a concern that overarches this conference on climate change, in which the issues are seen through the Smithsonian lenses of science, history, and art. Ginkgo biloba, commonly known as ginkgo or gingko also known as the maidenhair tree, is a species of tree native to China. It is the last living species in the order Ginkgoales, which first appeared over 290 million years ago. Fossils very similar to the living species, belonging to the genus Ginkgo, extend back to the Middle Jurassic approximately 170 million years ago. The tree was cultivated early in human history and remains commonly planted. Ginkgo leaf extract is commonly used as a dietary supplement, but there is no scientific evidence that it supports human health or is effective against any disease. Extracts of ginkgo leaves contain phytochemicals such as phenolic acids, proanthocyanidins, flavonoid glycosides, such as myricetin, kaempferol, isorhamnetin, and quercetin, and the terpene trilactones ginkgolides and bilobalides. The leaves also contain unique ginkgo biflavones, alkylphenols, and polyprenol. Here is a poem about the Ginkgo by written by the German poet Johann Wolfgang von Goethe: In my garden's care and favour From the East this tree's leaf shows Secret sense for us to savour And uplifts the one who knows. Is it but one being single Which as same itself divides? Are there two which choose to mingle So that each as one now hides? As the answer to such question I have found a sense that's true: Is it not my songs' suggestion That I'm one and also two?