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It may not be the tallest tree in the world but Sequoiadendron giganteum is the largest by volume, reaching up to 95 m in height and 12 m in diameter. On its introduction to Britain in 1853, the species was named Wellingtonia gigantea after the recently deceased Duke of Wellington. However, this scientific name was not legitimate because the name Wellingtonia had been used earlier for another plant (although it is still called Wellingtonia as a common name in the UK).

[KSP]

Kew Species Profiles

General Description
Giant by name and giant by nature, this huge Californian conifer is by volume the largest tree in the world.

Sequoiadendron giganteum can reach up to 95 m in height and 12 m in diameter. On its introduction to Britain in 1853, the species was named Wellingtonia gigantea after the recently deceased Duke of Wellington. However, this scientific name was not legitimate because the name Wellingtonia had been used earlier for another plant (although it is still called Wellingtonia as a common name in the UK).

Always on the lookout for new and exciting large trees, estate owners jumped at the chance of growing another impressive specimen and having the name Wellingtonia worked wonders as a marketing tool. Although planted less frequently now, it is quite common throughout the British Isles, particularly in large gardens and parks. The giant redwood, which can live up to 3,200 years, was formerly put in the swamp cypress family (Taxodiaceae), which is now placed in the cypress family (Cupressaceae).

Species Profile
Geography and distribution

Native to California in the United States, the giant redwood is found on the western slopes of the Sierra Nevada mountain range, where it occurs in about 75 distinct groves. It inhabits mixed conifer forests at 1,100 - 1,500 m above sea level.

Description

An evergreen tree with distinctive spongy red bark, the giant redwood can reach up to 95 m in height and 12 m in diameter. The deeply furrowed bark can be up to 60 cm thick. The branches form a rounded crown towards the top with individual branches sweeping downwards with upturned ends. The leaves are small and scale-like and are in spirals. Male and female cones are borne on the same tree, and are tiny in relation to the tree as a whole, the female ones measuring a mere 5-7 cm. The cones take at least two years to ripen; however, many cones remain green and unopened for anything up to 20 years. They are reddish-brown when mature and contain numerous, flattened, winged seeds.

Reproduction of the giant redwood

Natural bush fires are not as common as they once were in California, but are essential for giant redwood reproduction. The bark is fire-resistant, so the tree is left unharmed after a fire while other plant life around it is cleared. This is a prerequisite for seedlings to grow, helped along by a layer of ash as a seedbed. The heat from the fire also starts the process, as it causes the cones to open, dispersing their seeds on the wind.

Giant by name...

The largest living specimens are found in its native California, where the largest tree is known as 'General Sherman'. At the last measurement, it stood 84 m (275 ft) high, with a trunk circumference of 31 m (103 ft) at ground level. It is estimated to be around 3,200 years old.

The speed at which Sequoiadendron giganteum grows when young is nothing short of phenomenal. In Italy, a young tree reached a height of 22 m (72 ft) in just 17 years. Growth rates depend largely on the habitat and weather conditions, and while the tree can survive in temperatures as low as -30°C, it tends to flourish in a humid environment with dry summers and snowy winters.

Threats and conservation

The giant redwood has been rated as Vulnerable (VU) according to IUCN Red List criteria, populations having been reduced as a result of large-scale logging between 1856 and 1955. Measures taken to prevent bush fires also led to a build-up of undergrowth which may have reduced the growth of seedlings, which need a clearing to thrive. The majority of giant redwoods is now within National Parks (such as Yosemite, Sequoia and Kings Canyon); indeed 90% of wild populations are now protected. Land management and tree-planting schemes have been put in place to conserve the species.

Uses

Apart from being fire-resistant, the timber of Sequoiadendron giganteum has little commercial value, which makes the widespread felling of this tree during the nineteenth and twentieth centuries all the more unfortunate. The magnificent giant redwood is now a major draw for ecotourists from around the world, and it is seen as one of the flagship species for conservation in the United States. It has been widely planted as an ornamental tree in large parks and gardens in countries with a temperate climate, from Europe to New Zealand, and Canada to Chile.

Millennium Seed Bank: Seed storage

Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Description of seeds: Average 1,000 seed weight = 6.6 g

Number of seed collections stored in the Millennium Seed Bank: One

Giant redwood at Kew

The giant redwood can be seen growing in Redwood Grove, about halfway between the Pagoda and the River Thames at Kew, and can also be viewed from the Rhizotron and Xstrata Treetop Walkway. 

Christmas Tree at Wakehurst

During the winter you may also be able to enjoy the spectacle of England's largest growing Christmas tree, a towering 113-foot giant redwood, which is illuminated daily in front of the Mansion at Wakehurst, Kew's country estate in West Sussex.

Each year a team of expert tree-climbers from Wakehurst's woodland and conservation team spend a day, using ropes and specialist climbing gear, festooning a 113-foot giant redwood tree with 1,800 Christmas lights. The twinkling Christmas tree is a local landmark that can be seen for miles around - even from the air by pilots approaching nearby Gatwick Airport.

Distribution
USA
Ecology
Growing as an emergent in mixed montane conifer forests.
Conservation
Vulnerable (VU) according to IUCN Red List criteria.
Hazards

None known.

[EDGE]

Forest, F. et al. 2018. Gymnosperms on the EDGE. Scientific Reports 8: 6053. doi:10.1038/s41598-018-24365-4.

Conservation
Sequoiadendron giganteum is rated as Endangered (EN) according to IUCN Red List criteria and has received a EDGE score of 3, which places it in position 16 on the EDGE Gymnosperm list. It has a Evolutionary Distinctiveness of 47.81, ranked 43. More information on the EDGE Gymnosperm project here https://www.edgeofexistence.org.

[KSP]
Use
Ecotourism.

Native to:

California

Introduced into:

Austria, France

English
Giant redwood

Sequoiadendron giganteum (Lindl.) J.Buchholz appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Jun 1, 2012 Goldman, D.H. [2920], USA K000554703
Nov 1, 2000 Bracelin, H.P. [717] K000088887
Feb 24, 2000 Lobb, W. [436], California K000088885 isotype
Feb 1, 2000 Kuntze, O. [3169] K000088886
Feb 1, 2000 Stagner, H. [s.n.] K000088888
Feb 1, 2000 Thomas, J.H. [10390] K000088889
73846.000
73847.000
73848.000

First published in Amer. J. Bot. 26: 536 (1939)

Accepted by

  • Farjon, A. (2001). World Checklist and Bibliography of Conifers, ed. 2: 1-309. The Royal Botanic Gardens, Kew.
  • Farjon, A. (2010). A handbook of the world's Conifers 2: 533-1111. BRILL, Leiden, Boston.
  • Tutin, T.G. & al. (eds.) (1993). Flora Europaea ed. 2, 1: 1-581. Cambridge University Press.

Literature

Kew Species Profiles

  • Conifer Specialist Group (1998). Sequoiadendron giganteum. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.3. < www.iucnredlist.org>. Downloaded on 26 October 2010.
  • Farjon, A. (2005). A Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew.
  • Farjon, A. (2010). A Handbook of the World’s Conifers. E.J. Brill, Leiden & Boston.

Kew Backbone Distributions

  • Farjon, A. (2001). World Checklist and Bibliography of Conifers, ed. 2: 1-309. The Royal Botanic Gardens, Kew.
  • Tutin, T.G. & al. (eds.) (1993). Flora Europaea ed. 2, 1: 1-581. Cambridge University Press.

Art and Illustrations in Digifolia
Digital Image © Board of Trustees, RBG Kew

EDGE Gymnosperms
EDGE of Existence (Gymnosperms)
http://creativecommons.org/licenses/by-nc-sa/3.0

Herbarium Catalogue Specimens
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Backbone Distributions
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Science Photographs
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Species Profiles
Kew Species Profiles
http://creativecommons.org/licenses/by-nc-sa/3.0