The trunk forms a distinctive "armpit" under each branch. glyptostroboides is a fast-growing tree, exceeding 35 m (115 ft) in height and 1 m (3.3 ft) in trunk diameter by the age of 50, in cultivation (with the potential to grow to even greater dimensions). distichum, older trees may form wide buttresses on the lower trunk. While the bark and foliage are similar to another closely related genus of redwoods, Sequoia, M. glyptostroboides differs from the coast redwood in that it is deciduous, like Taxodium distichum (bald cypress). The cones are globose to ovoid, 1.5–2.5 cm (0.59–0.98 in) in diameter with 16–28 scales arranged in opposite pairs in four rows, each pair at right angles to the adjacent pair they mature in about 8–9 months after pollination. The pollen cones are 5–6 mm (0.20–0.24 in) long, produced on long spikes in early spring they are produced only on trees growing in regions with hot summers. Metasequoia glyptostroboides leaves are opposite, 1–3 cm (0.39–1.18 in) long, and bright fresh green, turning a foxy reddish brown in autumn.
Hua's collecting trip returned with several kilos of seed that were distributed over the next few months for growth trials to Chinese institutions the Arnold Arboretum, Missouri Botanic Garden, and elsewhere in the United States botanic gardens at Kew, Edinburgh, and other locations in the United Kingdom as well as botanic gardens in continental Europe and worldwide. In July 1947, the Arnold Arboretum of Harvard University provided $250 to fund an expedition by Zheng Wanjun's assistant Hua Jingchan (Ching-Shan Hwa 1921–present) to collect seeds for the arboretum from the Metasequoia type tree in Moudao, and trees in the nearby Metasequoia Valley (Shuishaba Valley). Professors Zheng Wanjun (Cheng Wan-Chun) and Hu Xiansu (Hu Hsien-Hsu) made the pivotal connection between Miki's fossil genus and the living samples in 1946, and provided the specific epithet " glyptostroboides", after its resemblance to the Chinese swamp cypress ( Glyptostrobus). The samples were determined to belong to a tree yet unknown to science, but World War II postponed further study. In 1943, Wang Zhan (Chan Wang, 1911–2000) of the National Bureau of Forest Research, the Ministry of Agriculture and Forests, Chongqing, collected samples from an unidentified tree in the village of Moudao ( 谋道 镇 formerly Motaochi, Maodaoqi or Modaoxi) in Lichuan County, Hubei province-now believed to be the same tree Kan discovered. This tree formed part of a local shrine, where villagers called it Shuǐshān 水杉 or "water fir". Unfortunately, while he collected some plant material, he did not attempt to identify or publish his findings. Though unaware of Miki's new genus, he recognized the unique traits of the tree.
In the same year, Kan Duo (Toh Kan, 1903–1961), professor of Forest Management, National Central University, Chongqing, (formerly Chungking) observed an enormous living specimen while performing a survey in Sichuan and Hubei provinces. He realized he had discovered a new genus, which he named Metasequoia, meaning "like a sequoia". Shigeru Miki from Kyoto University identified a divergent leaf form. While studying fossil samples of the family Cupressaceae, Dr. When the genus Metasequoia was first described in 1941, it was from Mesozoic Era fossils, none of which were less than 150 million years old. History Metasequoia glyptostroboides (dawn redwood) bonsai treeĪlthough it was commonly known from the fossil record from across the northern hemisphere, the dawn redwood was considered extinct until the mid-twentieth century. If the species had been discovered later, it might have become extinct before being investigated. The tree faces considerable risks of extinction in its wild range due to deforestation however, it has been planted extensively in arboreta worldwide, where it has proved a popular and fast-growing ornamental plant. It is a particularly well-known example of a living fossil species. In 1941, the genus Metasequoia was reported by paleobotanist Shigeru Miki as a widely distributed extinct genus based on fossils, before attracting considerable attention a few years later when small populations were found alive in central China. Although the shortest of the redwoods, it can grow to 167 ft (51 m) in height.
It now survives in the wild only in wet lower slopes and montane river and stream valleys in the border region of Hubei and Hunan provinces and Chongqing municipality in south-central China, notably in Lichuan county in Hubei. It is the sole living species of the genus Metasequoia, one of three genera in the subfamily Sequoioideae of the family Cupressaceae. Metasequoia glyptostroboides, the dawn redwood, is a fast-growing, endangered deciduous conifer.
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