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.