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Plant of the Week
Dawn Redwood
Latin: Metasequoia glyptostroboides
With only a limited amount of room in our gardens, it makes sense to use
plants that have multiple seasons of interest or at least a good story to tell.
The dawn redwood is one of the trees that has a good story to tell, and it’s a
good story dating back over 60 million years ago.
Dawn redwood has the distinction of first having been noticed as a part of the
fossil record in 1855. The fossils were first thought to be those of our native
bald cypress, but just weeks before the bombing at Pearl Harbor, a Japanese
scientist noticed that the fossils did not match any known tree so he
reclassified the fossil plant under a new name, Metasequoia.
Fossil records of dawn redwood have been discovered in Japan, western North
America and Greenland, indicating that it – like the ginkgo – once was very
widely distributed.
The dawn redwood is a deciduous conifer similar to bald cypress. It grows up to
100 feet tall with a narrow, pyramidal form while young, and a large, swollen
trunk. The leaves are feathery, light green and soft textured. Being a conifer
it does not have showy flowers. Seeds on adult trees are produced in a cone.
Tsang Wang, a forester employed by the National Central University in China,
happened upon an unusual tree in 1941 growing between rice paddies in the
Shuishaba Valley in south-central China on the Sichuan and Hubei Provencal
border.
The locals called the tree water pine and used its wood for cabinet making. He
collected pressed specimens of the foliage and sent them to Beijing where, in
the fall of 1946, they were finally associated with the fossil records and the
tree was identified as a living fossil.
Perhaps finding a living fossil plant is not as exciting as finding a living
dinosaur, but it’s still pretty big news and word of the discovery quickly was
received in Boston at Harvard’s Arnold Arboretum.
During the next growing season, Tsang, supported by funds from the Arnold
Arboretum and accompanied by Ralph Chaney a paleobotanist from the University of
California, flew to the valley to collect seeds just before the Bamboo Curtain
came down and sealed off China for the next 35 years.
Four pounds of seeds were collected, despite a government ban, and sent back to
the Arnold Arboretum for distribution. In subsequent years the area was explored
more thoroughly and about 1,000 trees were found in the valley with an elevation
of 3,400 feet. The area received about 50 inches of rainfall a year.
Today, the trees in the valley are protected by the Chinese government, but
during the Cultural Revolution several of the largest trees were cut.
The dawn redwood makes a fast growing specimen tree in the landscape, attaining
25 feet in height in 10 years. It should be planted in sites with good soil that
can be irrigated during dry spells. Unlike its look-alike cousin, the bald
cypress, dawn redwood will not tolerate dry sites.
By: Gerald Klingaman, retired
Extension Horticulturist
- Ornamentals
Extension News -
March 5, 1999
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