The dawn redwood: a living fossil

The dawn redwood (Metasequoia glyptostroboides) is the odd one out among the three redwoods, and it has the strangest history of any tree on our maps. It was named as a fossil before anyone knew it was still alive.

Found in the rocks first

In 1941 the Japanese palaeobotanist Shigeru Miki, working through fossil conifers, realised that a set of leaf and cone impressions long filed under the bald cypresses and the coast redwoods belonged to neither. The branchlets were arranged in opposite pairs rather than alternately, and the little cones sat on long stalks. He gave the fossil a new genus — Metasequoia, "like a sequoia" — and assumed, as everyone did, that it had been extinct for millions of years.

Then found alive

In those same years, in the mountains of central China, a large unfamiliar deciduous conifer was recorded standing beside a shrine in the village of Modaoxi, on the Sichuan–Hubei border. Local people knew it as shui-sha, the "water fir". Collections made in 1943 and 1944 reached Chinese botanists, and in 1946 Hu Hsen-Hsu and Cheng Wan-Chun matched the living tree to Miki's fossil. A genus described from stone turned out to be alive — one of the clearest "living fossils" ever found.

Seed around the world

In 1948 the Arnold Arboretum at Harvard funded an expedition to collect seed from the wild groves around Lichuan, in Hubei, and shared it with botanic gardens across the world. Within a year or two, dawn redwoods were growing in Britain — at Kew, at Cambridge, at Wakehurst, and in private gardens whose owners had followed the news. Almost every mature dawn redwood in this country descends from that 1948 seed.

A conifer that behaves like a broadleaf

What makes the tree memorable in person is that it is deciduous. In autumn the soft, feathery foliage turns a foxy russet-pink and falls, leaving a bare, narrowly conical tree through winter — behaviour that surprises people who expect a "redwood" to be evergreen. The branchlets are held in opposite pairs, which is the quickest way to separate it from the very similar swamp cypress (Taxodium), whose foliage is alternate. Older trunks are deeply fluted and buttressed, often with curious hollows or "armpits" beneath the branch joins.

Reading it in Britain

Our dawn redwoods are young — many are younger than the people who planted them — so they lack the bulk of the giant sequoias planted a century earlier. This is a different story from the 1850s redwood craze: a recent, deliberate introduction, made because a tree believed lost had been found. When you stand under one, you are looking at a species that botanists thought extinct within living memory.

Where we list a dawn redwood's planting date we look for the same corroboration as any record — see History in Britain. If you know a notable dawn redwood we are missing, especially an early one grown from the 1948 seed, add it.