The Dawn Redwood (Metasequoia glyptostroboides) is a remarkable and ancient tree species. Once believed to exist only in the fossil record, it was rediscovered in central China in the 1940s, earning it the moniker “living fossil.” This rediscovery excited the botanical world, offering a direct link to prehistoric forests. Known for rapid growth and impressive heights, its distinctive appearance makes it a favored choice for large landscapes and arboreta.
A Conifer That Loses Its Leaves
The Dawn Redwood is unique among its conifer relatives because it is a deciduous conifer, meaning it sheds its needles annually. While most conifers, such as pines and spruces, are evergreen and retain their needles year-round, the Dawn Redwood follows a different biological strategy. This adaptation is shared by only a few other conifers, like the Bald Cypress (Taxodium distichum).
Fossil evidence indicates that its ancestors were once widespread across the Northern Hemisphere, including regions that experienced colder climates. Shedding needles allows the tree to conserve water and reduce damage from freezing temperatures and heavy snow loads during the dormant season, an advantage in temperate zones. This contrasts with evergreen conifers, which have evolved to withstand winter conditions with their persistent foliage, often having waxy coatings or other features to prevent water loss. The Dawn Redwood’s ability to thrive in diverse environments, partly due to its deciduous habit, highlights its resilience and unique place in botanical history.
The Annual Cycle of Leaf Drop
The annual cycle of leaf drop in Dawn Redwoods is a visually striking event, transforming the tree’s appearance dramatically with the changing seasons. In spring, delicate, bright green needles emerge in flat sprays, maturing to a lush emerald green during the summer months. As autumn progresses, these needles undergo a vibrant metamorphosis, changing from green to brilliant shades of rusty orange, bronze, and reddish-brown, providing a stunning display before they are shed.
This process typically occurs in late autumn to early winter, usually between October and December, depending on the climate. After turning color, the needles fall, creating a soft, reddish-brown carpet beneath the tree. This shedding process is distinct from broadleaf deciduous trees, which drop broad leaves, as the Dawn Redwood sheds its fine, feathery needles. The complete shedding of foliage leaves the tree with a bare silhouette throughout the winter, ready to burst forth with new growth in the spring.
Identifying This Unique Tree
Identifying a Dawn Redwood is straightforward, particularly when observing its distinctive features. Its trunk often develops an attractive, buttressed or fluted base as the tree matures, broadening significantly at the ground level. The bark is reddish-brown and tends to be vertically fissured, sometimes exfoliating in ribbon-like strips, adding to its visual appeal.
The needles are linear, soft to the touch, and arranged oppositely along the twigs, which is a distinguishing feature from many other conifers. Unlike some conifers, the entire branchlet, including the needles, will drop in the fall. The tree also produces small, oval to globose cones, typically 1.5 to 2.5 centimeters in diameter, with scales arranged in opposite pairs. Its deciduous nature, especially evident in the fall when its needles turn a distinct coppery-brown before dropping, serves as a primary distinguishing feature from most evergreen conifers, making it relatively easy to identify even in winter.