Ginkgo: The Tree That Time Forgot

  • Peter Crane
Yale University Press: 2013. 408 pp. $40 9780300187519 | ISBN: 978-0-3001-8751-9

Biographies seem to come in two sorts. The first is a dense compilation of deeds and misdeeds, dates and details of the dead; the second, a hagiography of celebrities still alive and kicking.

Ginkgo is neither. Its subject should by rights be dead, but having outlasted the dinosaurs, is still very much with us. This biography of the ginkgo tree offers a potent mix of science, history and culture, exploring how plants have changed our lives and our planet. And Peter Crane, a palaeobotanist by trade and all-round botanist by nature, is the perfect person to tell the tale.

Ginkgo trees can live for thousands of years. Credit: DAVID STEPHENSON/LEXINGTON-HERALD-LEADER/MCT/GETTYIMAGES

Lucidly and accessibly, he takes us from the living plant, through its long and fascinating past as seen in the fossil record, and then returns us to the present in sections on the ginkgo in culture and the future of diversity. This tree, he shows us, can be seen as a metaphor for all life on Earth — seemingly fragile, but actually tough and likely to outlive Homo sapiens. With its meticulous footnotes, satisfying referencing and gripping narrative, I can see this book becoming a commuter's favourite for scientists and general readers alike.

Ginkgo biloba, as the maidenhair tree was named by the great Swedish botanist Carl Linnaeus, is one of a kind. It is a biodiversity loner, the only species in its genus, family and order. This was not always the case, as Crane shows. Ginkgo relatives first appear in the fossil record more than 200 million years ago, and the lineage has hung on through great extinctions. Long ago, Ginkgo biloba had many relatives, but they have all since died out, as it almost did itself.

As he traces these species' amazing journey, Crane introduces key concepts in evolution — the part extinction plays in producing current patterns of distribution, the fact that where things are not found is as important as where they are, and the role of contingency in creating today's diversity. I loved his equation of the stunning plant-fossil trove in Scotland's Rhynie Chert with the Burgess Shale of Canada, that phenomenal array of Cambrian life-forms made famous by Stephen Jay Gould's Wonderful Life (W. W. Norton, 1989). There is another book in waiting there.

Crane's enthusiasm for fossil-hunting is very real. He recounts a stop in 1982 on a road in North Dakota, where he discovered some perfectly preserved ginkgo leaves and seed fossils from the Late Palaeocene (58.7 million to 55.8 million years ago). This extinct species is now known as Ginkgo cranei, but Crane is more taken with the joy of discovery than the honour of having a plant named for him.

As for the living tree, Crane fills us in on some of its peculiarities, not least its swimming sperm — studied by the reproductive-rights pioneer Marie Stopes during her career as a biologist — and the strange stalactite-like growth it uses for propagation. I went straight out to look at the ginkgo in front of London's Natural History Museum with new eyes.

Ginkgo ends with a beautiful section on the importance of this tree to human culture. It is revered for its longevity (the most venerable is some 3,500 years old) and beautiful form in China, Japan and Korea, and is one of the commonest street trees in the temperate zone in the West. The tree's loveliness is counterbalanced by a distinct autumnal odour: in Manhattan, where one-tenth of street trees are ginkgos, butyric acid in the seeds' fleshy covering gives off a whiff of rancid butter.

As Crane aptly puts it, its charisma — a mixture of unusual form, strange leaves and sheer staying power — has been an important element in its success and symbiosis with humans. Giant ginkgos are lovingly cared for and replaced when they start to die: the tree at London's Royal Botanic Gardens at Kew, planted some 250 years ago, is cared for as well as any national monument made by human hands.

The ginkgo was common over what is now the Northern Hemisphere between 100 million and 40 million years ago, but is elusive in the 'wild' today. Putatively wild ginkgos are known only from a couple of places in China, and they might be relics of old monasteries or human cultivation. Does it matter? On one level, no: that this species is still with us is itself to be treasured. On another, it does.

Earth's biodiversity has persisted through aeons, but no species has ever affected the planet as we have. Crane provides a wonderful precis of the politics of conservation, and how our own short ecological memories mean we often don't see the forest for the trees, however culturally important. People care for ginkgo trees because they are seen as special. But what of the rest of biodiversity? How can we conserve what we do not know?

The renowned naturalist Alfred Russel Wallace summed it up beautifully in 1863, saying that future generations “will charge us with having culpably allowed the destruction of some of those records of creation [species] which we had it in our power to preserve”.

Ginkgo will inspire you to know and care for the organisms with which we share this planet in a new way.