Tuesday, September 1, 2009

Dawn Redwood

This tree was first discovered in 1941 when a Japanese paleobotanist was reclassifying fossils that had been erroneously identified as Sequoia and Taxodium. He determined that not only were they fossils of a different species, they needed to be placed in a new genus. Given the tree’s similarities to the Coast (or California) redwood (Sequoia sempervirens), he named the new fossil genus Metasequoia.

Meanwhile, in Modaoqi on the Sichuan-Hubei border, a Chinese forester came across a small population of a tree he had never seen before. It was unknown and left unstudied until after the war. It turned out to be the same tree that was identified in fossil form as Metasequoia. The tree was given its species name, glyptostroboides, because of its resemblance to Glyptostrobus, the Chinese swamp cypress. The common name, dawn redwood, emphasizes the tree's early fossil record.

The dawn redwood was introduced to the United States and Europe around 1948. (It was actually re-introduced to the United States. There are fossils from California that show it inhabited the continent about 15 million years ago.)

The dawn redwood is a conifer. Here are two unripe cones.

Most conifers are evergreen, but the dawn redwood is deciduous. These leaves will turn reddish-brown and will be shed in the fall.

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