Home & Garden Columns

City’s Reunion of Trees Includes Ancient Dawn Redwood

By Ron Sullivan Special to the Planet
Tuesday April 18, 2006

The dawn redwoods don’t mind the soggy weather; they’re leafing out more or less on schedule. I suppose they evolved with wetter weather to begin with, so no surprise there. In other ways, this tree has been full of surprises. 

There are dawn redwoods, Metasequoia glyptostroboides, in several private gardens around Berkeley, and on the UC campus (right around the corner from Trader Vic Bergeron’s oddly squatting sabertooth cat statue, among other places) and in the UC Botanical Garden; there are a couple of young ones beside the Joseph Charles tennis courts on MLK at Oregon. People who’ve moved into properties with established dawn redwoods have been unpleasantly surprised in autumn when the leaves turned russet and fell. Some have—horrors!—had the “dead” trees cut down. But this species, like the Southeastern baldcypress (Taxodium distychum) it resembles and unlike our native coast redwoods, is naturally deciduous.  

Right now its new leaves are tender, pale green feathers against pale red-brown, shreddy bark. The trunk of every one I’ve seen that’s younger than a few hundred years is vertically rippling, muscular, tapering from a broad base to the narrow spire of the tree’s single leader.  

Dawn redwood is one of few living species that was named and classified from fossils alone, long before anyone in the scientific community that uses those Linnean binomials had seen a living individual. In a way, it’s a living fossil, like our coastal Sequoia sempervirens and Sequoiadendron giganteum, their massive relative in the Sierra Nevada. All are relict species, survivors of forests and families that existed over much greater territories in a different world climate several million years ago. Dawn redwood fossils have been found around the northern hemisphere from Spitsbergen through Alaska and our Midwest to Greenland.  

The interests of quite various academics came together to identify and find this relic. In 1941, a Japanese paleobotanist, Shigeru Miki, decided that the Pliocene fossils he was seeing weren’t just another Taxodium after all, in fact weren’t quite like anything else, and named them their species binomial. News like this didn’t travel fast across the battle lines of World War II.  

That same year, a Chinese forester-professor named T. Kan noticed an interesting tree on a roadside in Szechuan. As it was winter and the tree was bare, he couldn’t collect the usual specimens, but he asked a local resident to collect some in spring. The specimens weren’t identified until they’d passed through many hands over several years, and in 1946 reached someone who’d read Miki’s publication, one Dr. H. H. Hu of the Fan Institute in (then) Peiping. He matched the living samples with Miki’s recently named fossils.  

Dr. Hu wrote to Dr. Elmer D. Merrill of Harvard and Dr. Ralph Chaney of UC Berkeley to announce the find and request help in preserving the species. Merrill sent $250, enough to fund a seed-gathering trip by Hu’s colleagues, and the seed was redistributed to interested gardens and arboretums all over the world. Chaney, however, took a different approach. He wanted to meet this living fossil on its home turf. 

UC’s Chaney wanted to meet this old-new tree in the flesh. He’d traveled to China with Roy Chapman Andrews’ famous 1925 Mongolia-Gobi Desert expedition, which had discovered the first Velociraptor fossils—and, in fact, had collected unrecognized dawn redwood fossils. Over 20 years later, Chaney’s health was barely up to the trip; he had to be carried in a rude palanquin for part of the way, through freezing storms on treacherous trails.  

He’d already met the type specimen, the 480-year-old, 112-foot-tall individual whose seeds had been sent out and whose lineaments were used to describe the species. The hard part was a farther trip, to see a whole forest of dawn redwoods.  

He saw there a mixed forest of broadleaf trees—birch, beech, oak, sweetgum, maple, chestnut—in which the dawn redwood was a citizen, as its fossils had suggested was the case through its ancient range. “It’s like a botanical alumni reunion,” he said. “This is what much of the world looked like a million centuries ago.” 

Such a reunion takes place not only in arboretums around the world, but on out city streets, planted with many of those trees now. Continents and climates drift, and humans drift too, just faster. 

 

 

Photograph by Ron Sullivan. 

A young dawn redwood just starting to leaf out. This one lives beside the tennis courts at Oregon Street and Martin Luther King Jr. Way in South Berkeley. The muscular trunk is a good fieldmark for the species.