By Oliver Sacks
Today in New York—November 13th—leaves are falling, drifting, skittering everywhere. But there is one striking exception: the fan-shaped leaves of the ginkgo are still firmly attached to their branches, even though many of them have turned a luminous gold. One sees why this beautiful tree has been revered since ancient times.
Carefully preserved for millennia in the temple gardens of China, ginkgoes are almost extinct in the wild, but they have an extraordinary ability to survive the heat, the snows, the hurricanes, the diesel fumes, and the other charms of New York City, and there are thousands of them here, mature ones bearing a hundred thousand leaves or more—tough, heavy Mesozoic leaves such as the dinosaurs ate. The ginkgo family has been around since before the dinosaurs, and its only remaining member, Ginkgo biloba, is a living fossil, basically unchanged in two hundred million years.
While the leaves of the more modern angiosperms—maples, oaks, beeches, what have you—are shed over a period of weeks after turning dry and brown, the ginkgo, a gymnosperm, drops its leaves all at once. The botanist Peter Crane, in his book “Ginkgo,” writes that, in relation to a very large ginkgo in Michigan, “for many years there was a competition to guess the date on which the leaves would fall.” In general, Crane says, it happens with “eerie synchronicity,” and he quotes the poet Howard Nemerov:
Late in November, on a single night
Not even near to freezing, the ginkgo trees
That stand along the walk drop all their leaves
In one consent, and neither to rain nor to wind
But as though to time alone: the golden and green
Leaves litter the lawn today, that yesterday
Had spread aloft their fluttering fans of light.
Are the ginkgoes responding to some external signal, such as the change of temperature or light? Or to some internal, genetically programmed signal? No one knows what lies behind this synchronicity, but it is surely related to the antiquity of the ginkgo, which has evolved along a very different path from that of more modern trees.
Will it be November 20th, 25th, 30th? Whenever it is, each tree will have its own Night of the Ginkgo. Few people will see this—most of us will be asleep—but in the morning the ground beneath the ginkgo will be carpeted with thousands of heavy, golden, fan-shaped leaves.