Sequoiadendron giganteum (giant sequoia; also known as giant redwood, Sierra redwood, Sierran redwood, Wellingtonia or simply big tree—a nickname also used by John Muir[2]) is the sole living species in the genus Sequoiadendron, and one of three species of coniferous trees known as redwoods.
Giant sequoia specimens are the most massive individual trees in the world. They grow to an average height of 50–85 m (164–279 ft) with trunk diameters ranging from 6–8 m (20–26 ft). Record trees have been measured at 94.8 m (311 ft) tall. The specimen known to have the greatest diameter at breast height is the General Grant tree at 8.8 m (28.9 ft)
The oldest known giant sequoia is 3,500 years old based on dendrochronology. Giant sequoias are among the oldest living organisms on Earth. Giant sequoia bark is fibrous, furrowed, and may be 90 cm (3 ft) thick at the base of the columnar trunk. The bark provides significant protection from fire damage. The leaves are evergreen, awl-shaped, 3–6 mm (1⁄8–1⁄4 in) long, and arranged spirally on the shoots.
John Muir wrote of the species in about 1870:
“ Do behold the King in his glory, King Sequoia! Behold! Behold! seems all I can say. Some time ago I left all for Sequoia and have been and am at his feet, fasting and praying for light, for is he not the greatest light in the woods, in the world? Where are such columns of sunshine, tangible, accessible, terrestrialized? ”
Because of its size, the tree has been studied for its water pull. Water from the roots can be pushed up only a few meters by osmotic pressure but can reach extreme heights by using a system of branching capillarity (capillary action) in the tree's xylem (the water tubules) and sub-pressure from evaporating water at the leaves.[10] Sequoias supplement water from the soil with fog, taken up through air roots, at heights to where the root water cannot be pulled
Giant sequoia is a very popular ornamental tree in many areas. It is successfully grown in most of western and southern Europe, the Pacific Northwest of North America north to southwest British Columbia, the southern United States, southeast Australia, New Zealand and central-southern Chile. It is also grown, though less successfully, in parts of eastern North America.
Giant sequoias are grown successfully in the Pacific Northwest and southern US, and less successfully in eastern North America. Giant sequoia cultivation is very successful in the Pacific Northwest from western Oregon north to southwest British Columbia, with fast growth rates. In Washington and Oregon, it is common to find giant sequoias that have been successfully planted in both urban and rural areas. In the Seattle area, large specimens exceeding 90 ft (27 m) are fairly common and exist in several city parks and many private yards (especially east Seattle including Capitol Hill, Washington Park, & Leschi/Madrona, as well as Tacoma's Jefferson Park).
Several impressive specimens of Sequoiadendron giganteum can be found in the South Island of New Zealand. Notable examples include a set of trees in a public park of Picton, as well as robust specimens in the public and botanical parks of Christchurch and Queenstown There are also several in private gardens in Wanaka. There is also a tree at Rangiora High School, which was planted for Queen Victoria's Golden Jubilee and is thus over 125 years old