by Jim Atwater
Prior to World War II as far as the world was concerned the dawn redwood (Metasequoia glyptostroboides) no longer existed. In 1941 a Japanese paleobotanist while digging in clay deposits near Tokyo unearthed fossils of a plant believed to have originated in the late Cretaceous period 100 million years ago and extinct for more than a million years.
Coincidentally, that same year 2000 miles to the west, a Professor T. Kan of the National Central University while traveling from Hupeh to Szechwan Province in central China was attracted by a large apparently deciduous tree that the local natives referred to as the “water fir” and worshipped as a deity. However it was only after the war’s end and several failed attempts that specimens of this mysterious plant were recovered and sent to the Institute of Biology in Beijing where it was identified as a surviving member of the fossil genus discovered earlier in Japan. Thus the world was introduced to this “living fossil,” a relict from the age of the dinosaurs of 100 million years ago. This was the botanical find of the 20th century.
Through fossil remnants science has been able to trace its long journey from eastern Siberia. It appears to have migrated both southward to Japan and eastern China and across the Bering Strait land bridge to North America moving as far south as the Mexican border. About 60 million years ago it expanded its range above the Artic Circle, but then contracted at about 35 million years ago, undertaking a lateral expansion into central Asia. By the Miocene period 5 million years ago it had vanished from both North America and Eurasia with the exception of the Japanese Islands. No fossils have been found in China since, only in Japan suggesting that the dawn redwood is a recent newcomer to a compact area of about 300 square miles in the Hupeh-Szechuan area of south-central China. How did it make this trip? Probably by a land bridge between southern Japan and the mainland within the last 2 million years. Within this present range there is significant compression, with the bulk of living plants concentrated in the Shui-Hsa Valley forming a narrow corridor 15.5 miles long and one mile wide. Now the mystery is, how was such a remarkable specimen of horticultural antiquity overlooked by the keen-eyed plant explorers of the last 200 years – intrepid investigators like Armand David, Paul Farges, Augustine Henry or E. H. “Chinese” Wilson (who alone made six expeditions to Asia over a 16-year period introducing over 1500 new Asian plants to the western world). The answer may be found in the fact that China is a vast land that in the 19th and early 20th centuries confronted the traveler with the most forbidding obstacles due to its primitive communications network. Travel by wild rivers and treacherous nearly impassable trails would have been the norm.
Upon learning of this new species, the Arnold Arboretum in Boston arranged for an expedition to collect seeds of this botanical phoenix, happily just before the “bamboo curtain” descended in 1948 placing a prohibition against foreign travelers that would last for thirty-two years. The Arnold promptly distributed packets of these seeds throughout Europe and North America. Initially there was great concern over the hardiness of this “living fossil” as its refuge in China was relatively wet and mild, much like our southeast coastal region in North America. Although it prefers warm summers, cold winters and plenty of water it has shown remarkable adaptability which should not come as a surprise considering it has survived 100 million years with little change in its morphology. It has established itself globally throughout the northern hemisphere. Related to the giant sequoia and coast redwood of California, it will not achieve their monumental stature. The largest in China is a 450-year-old tree over 155’ in height, although trees over 100’ with a diameter of 5’ or more (measured at 5’ above the ground) are common. A 165’ high plant 7’ in diameter was killed by lightening in 1954. In North American it does best in the east. There is a grove at Broadmeade Park in Princeton, NJ with trees 125’ in height and adding 2’ a year. Perhaps the largest in North American is in the Bailey Arboretum at Locust Valley on the north shore of Long Island; this tree is over 100’ tall with a trunk of 5.62’ in diameter (1998). This may be the largest in total bulk outside of China of the trees planted in1948 or later.
A geologist friend of mine on the faculty of St. Lawrence University conducts summer digs in the west with students. Three years ago they discovered a 9’ length of the fossilized trunk of what they believe is a dawn redwood over 8’ in diameter. It is now on permanent display at Watford City, North Dakota and estimated to be about 55 million years old. For those who would like to check it out Watford is a little south of Williston in the northwest corner of the state.
In 1948 the Monroe County Parks Department received seeds from the Arnold Arboretum’s earliest distribution. Three original trees from these seeds are presently growing in our park system. Two are in Durand Eastman Park near the intersection of Pine Valley and Sweet Fern Roads. A third is on the southeast corner of South Goodman and Highland Avenue in Highland Park.