Metasequoia glyptostroboides / dawn redwood

Metasequoia glyptostroboides, as described in 1948 by Wan Chun Cheng and Hu Hsen Hsu, in Bulletin of the Fan Memorial Institute of Biology, is commonly known as dawn redwood, water fir, or water larch; as well as 水杉 (shui shan) in the Chinese language, which literally translates to "water fir." It is the sole species in Metasequoia S. Miki (1941), a genus initially described from fossil material. Shigeru Miki (1901–1974) of Kyoto University, studying fossil samples of the family Cupressaceae, isolated a divergent leaf form that led him to describe a new genus, which he named Metasequoia, meaning "like a sequoia." Only in 1946 was the connection made between Miki's new genus and the living samples identified by Kan and Wang. Professor Hu Xiansu (1894–1968) is credited with making this important connection, and providing the specific epithet "glyptostroboides," after its resemblance to the Chinese swamp cypress (Glyptostrobus).

Description. Dawn redwood is a deciduous coniferous species of tree which will quickly grow to mature heights of 145 feet (45 m) tall, with a tapering trunk broadening to the buttressed base. Its crown is conical when young, broad and rounded with age.

• Bark is reddish-brown when young, becoming darker, greyish, fissured, exfoliating in long, narrow strips.
• Branches grow ascending. Branchlets are glabrous, of two kinds, persistent and deciduous. The persistent bright, reddish-brown when young, shallowly ridged, carrying the deciduous branchlets, numerous vegetative buds and a few leaves. The green deciduous branchlets grow up to about 3 inches (7.5 cm) long, often longer on young trees.
• Leaves (needles) are linear, flattened, straight or slightly curved, about 0.5 inch (12 mm) long and 0.06 inch (1.6 mm broad on mature trees, but on seedlings and young trees are generally 1 to 1.25 inches (24 - 32 mm), sometimes up to 2.5 inches (64 mm) long. The upper surface is bright green, with a narrowly grooved midvein, the under surface bearing obscure lines of stomata, lighter green or slightly glaucous, the midrib slightly raised. In autumn, the leaves turn reddish-brown before they are shed with the deciduous branchlets.
• Seed cones are short and cylindrical, up to 0.8 to 1 inch (20 - 25 mm) long, terminal, solitary and pendulous on sparsely leaved lateral branchlets.

Distribution. This species is native to China. Its primary occurrence is near the Sichuan-Hubei border, ca. 30°10'N, 108°45'E, with an outlying occurrence in northwestern Hunan province at elevations of 2,400 to 4,800 feet (750 - 1,500 m) above sea level. It is also found in eastern Sichuan, southwestern Hubei, and northwestern Hunan provinces, at 2,400 to 4,800 feet (750 - 1,500 m) elevation, where it is typically found on shady, moist sites such as ravines and stream banks.

Hardy to USDA Zone 4 — cold hardiness limit between -30° and -20°F (-34.3° and -28.9°C).

Attribution from: Wikipedia, The Free Encyclopedia