Of interest this week at Beal...
Dawn Redwood
Metasequoia glyptostroboides
W. J. Beal
Botanical Garden
Family: the Redwood family, Taxodiaceae
Also called Chinese water fir
The Dawn redwood, Metasequoia glyptostroboides, has certainly one of the most noteworthy
histories, both in geological time, and in its human-contact history. It has survived to our
time since the late Cretaceous period, the last third of the Mesozoic era. This species is
in fact one of a handful of extant plants that were known from fossils before they were
noted in the present. There are so many excellent Dawn redwood fossil sites from the
early Tertiary, the time after the Cretaceous and the dinosaurs, in the American West, that
Metasequoia has been designated as Oregon’s official state fossil.
In modern times, Dawn redwood was first noted in the winter of 1941 by Professor T.
Kan of the Department of Forestry of the National Central University while traveling from
Hupeh to Szechuan. He saw a giant tree the locals called a shui-sa, or water fir, but, as it
was winter and it had no leaves, no collection was made. Professor Kan requested that
the principal of the local agricultural high school collect specimens, but this apparently
did not happen. In the summer of 1943 (or 1944 depending on the author) while on an
expedition to Shen Nong Jia in northwestern Hubei, Chan Wang of the National Central
Bureau of Forest Research became ill and took refuge at the Wan Xian Agricultural School
and was told by the principal about a huge unknown tree, about 100 km away. He changed
his plans and went there where he collected some branches and found some cones on the
roof of a small temple nestled beneath the tree (new cones were out of reach). Eventually,
specimens made it to W. C. Cheng and H. H. Hu who first recognized that this new
species belonged to a genus recently (1941) described by Miki, from fossils, in Japan. Seeds
were first collected in 1947 by W. C. Cheng who sent some to Dr. Merrill, of the Arnold
Arboretum in 1948 (and simultaneously to Europe as well). Dr. Merrill sent them to some
76 institutions and botanists to found the North American population.
In the late 1980s, the remnants of a mummified forest were found on Axel Heiberg Island
in the Canadian Arctic islands. This deposit of Eocene age (approximately 45 million years
old) is mostly comprised of Dawn redwood forest debris from a time when the Arctic was
The seeds of Dawn redwood, Metasequoia glyptostroboides,
are winged for distribution by wind. Ascending to a height of at
least 170 feet (52 meters) affords an excellent launching altitude
for seed distribution in their native mountainous terrain in south
central China. In warmer periods of Earth history, Dawn redwood
was much more widely distributed in the northern hemisphere.
much warmer and more moist. This treasure trove of ancient forest litter is not actually
fossilized, just dried and slightly compressed. Some unthinking folks have actually burned
some of the ancient logs as firewood. Since these islands have not moved far since Eocene
times, these specimens demonstrate that a forest, accompanied by crocodilians and
primates survived in a place that was in darkness for three months out of every year.
Dawn redwood trees are robust and fast-growing. They can be acquired from nurseries and
seem to flourish in our temperate climate again, after a break lasting millions of years.