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.