Forest Preserve District of Cook County, Illinois
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The Ginkgo and the Dawn Redwood
Nature Bulletin No. 247-A   December 3, 1966
Forest Preserve District of Cook 
Seymour Simon, President
Roland F. Eisenbeis, Supt. of Conservation

THE GINKGO AND THE DAWN REDWOOD
For a mile or more along each side of Harlem Avenue, one of the main thoroughfares on the west side of Chicago, there is a row of small graceful trees which were planted there as seedlings about twenty years ago. At this season their leaves have fallen and they appear much the same as other trees in winter. But looks are deceiving because this is the Ginkgo, or Maidenhair Tree, and one of the strangest trees in the world -- a living fossil.

Until their seeds were brought to Europe and this country, this tree had been known only in the sacred groves around temples in China and Japan. All of its wild ancestors seem to have disappeared. We know that back in the age of dinosaurs there were many kinds of maidenhair trees because, throughout the northern hemisphere, we find their curious fan-shaped leaves in the same layers of rock as the fossils of those reptiles. Of all that large group, the ginkgo remains as the only tree of its sort living in the world today, and the fossil record shows that it has survived, unchanged, for at least a hundred million years.

The ginkgo is not a fern, nor a pine, nor a hardwood tree, but a combination of the features of all three. Its small yellowish plum-like fruit has a foul-smelling pulp enclosing a silvery nut with a sweetish resinous edible kernel. The fruit and the pollen-bearing catkins are borne on separate trees. The ginkgo has smooth light-gray bark and attains a height of 60 to 80 feet. Because it is hardy and remarkably free from pests, it has become increasingly popular for shade-tree planting on city streets and in parks.

Only a few years ago, another "living fossil" was discovered in a remote bandit-infested mountain valley of Central China. It has been named the Metasequoia, or Dawn Redwood, because it appears to be the ancestor of the Redwood and the Big Tree, or Giant Sequoia, of California. It was supposed to have become extinct many millions of years ago, but, from fossil remains of its leaves, twigs and cones found in rocks often 100 million years old, it was known to have been widespread over the temperate regions of the northern hemisphere.

The discovery, in 1944, of a living dawn redwood -- 64 inches in diameter and 98 feet tall -- towering above a small temple in the midst of rice paddies more than 100 miles northeast of Chungking in Szechwan Province, reads like a fiction thriller. Many people if different races and classes played a part in this most outstanding botanical discovery of the century. In March, 1948, Dr. Ralph W. Chaney, a specialist on fossil plants at the University of California, flew with a companion to Chungking. From there they traveled by boat down the Yangtse River, and then inland over rocky trails under the protection of armed guards to see this tree. Later, they found small groves of dawn redwoods growing in sheltered mountain ravines in company with birches, chestnuts, sweet gums, beeches and oaks -- the same hardwoods we have here in our country.

The most surprising feature of the dawn redwood is that, unlike the evergreen sequoias, it sheds its leaves in autumn. Further, its cones are borne on long naked stems and the leaves are arranged in opposite pairs on the twigs instead of alternately. Their branches slant upward instead of growing horizontally and turning down at the tips, as do those of the sequoias. Its seeds are small wafer-like discs similar to a flake of rolled oats. Some of these seeds were brought back, have been planted, and young dawn redwoods are growing in several places in the United States, including Cook County.


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