Living Fossil – Dawn Redwood

Did you know that Reiman Gardens offers visitors the chance to see a living fossil? No, I’m not referring to the topiary dinosaurs in the Children’s Garden. The living fossil in reference is the Dawn Redwood, Metasequoia glyptostroboides.

This conifer was first described in 1941 based only on fossil evidence. At that time, it was believed to have been extinct for millions of years. This hypothesis was proven false only 6 years later in 1947, when a small stand of unidentified trees in Southwest China was found to belong to the already described fossil species. After discovering that the Dawn Redwood was in fact not extinct, the Arnold Arboretum of Harvard University sent an expedition to collect seeds from the discovery site. The seedlings grown from this seed were then distributed to universities and arboreta around the world in an attempt to preserve the species.

From fossil data, the Dawn Redwood is known to have existed as many as 50 million years ago. It is the sole living member of the genus Metasequoia, which literally means “almost a sequoia.” As this name implies, the Dawn Redwood is closely related to the Coast Redwood (Sequoia sempervirens) and the Giant Sequoia (Sequoiadendron giganteum). In fact, these three species completely comprise the Cupressaceae subfamily Sequoioideae, or the redwood subfamily. While the bark and foliage of the Dawn Redwood are similar to the other redwoods, it is distinct in that it is deciduous and develops a widened trunk-base as it matures, not unlike the Bald Cypress (Taxodium distichum). The Dawn Redwood features feathery, fern-like foliage that is soft to the touch. New growth is light green, maturing to a deep green in the summer, and eventually turning red-bronze and falling off in autumn. Although it is the shortest of the redwoods, the Dawn Redwood can easily reach 70 to 100 feet in height. In the wild, trees have been found to be more than 150 feet tall.

Though the Dawn Redwood is considered endangered in its natural range, it has become a popular ornamental tree in parks and gardens worldwide. It is a vigorous grower, hardy to USDA Zone 5, and prefers full sun. Much like Bald Cypress, the Dawn Redwood requires adequate water availability, and will thrive in areas with standing water. As one would expect, Metasequoia grows very quickly; individuals planted in the 1940s have already exceeded 80 feet in height. For this reason, they may grow too large for smaller gardens. With enough space, however, the Dawn Redwood can be an attractive and impressive addition to the landscape.

If you’d like to see a Dawn Redwood in person, you can find one here at Reiman Gardens just south of the Home Production Garden. Consider this your invitation to come see a fossil come to life!

http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a396

http://www.monumentaltrees.com/en/trees/dawnredwood/dawnredwood/

http://www.conifers.org/cu/Metasequoia.php

By Heather, Plant Collections & Records Intern