Sequoiadendron giganteum description

The President, volume 1287.1 m³ [Robert Van Pelt].

Foliage and immature seed cones on an ornamental specimen in Seattle (USA) [C.J. Earle, Mar-1999].

Foliage and pollen cones from an ornamental specimen [C.J. Earle, Mar-1999].

Seed cones and seeds [Dr. Linda B. Brubaker].

An ornamental specimen ca. 25 m tall in Seattle (USA) [C.J. Earle, Mar-1999].

The Oregon Tree, a large specimen in the Giant Forest, showing bark and a typical fire scar [Dr. Linda B. Brubaker].

Sequoiadendron giganteum (Lindley) Buchholz 1939

Common Names

Giant sequoia, bigtree, Sierra-redwood (1).

Taxonomic notes

The sole species in Sequoiadendron Buchholz 1939. Syn: Wellingtonia gigantea Lindley 1853; Sequoia gigantea (Lindley) Decaisne 1854, not Endlicher 1847. The latter homonym reflects the species' former inclusion in Sequoia, a conservative placement that still has merit (Doyle 1945; Schwarz & Weide 1962) (1).

Description

For the genus: "Trees giant, evergreen. Branchlets terete. Leaves alternate, radiating. Adult leaves mostly needlelike, triangular in cross section, somewhat divergent to strongly appressed; abaxial glands absent. Pollen cones with 12-20 sporophylls, each sporophyll with 2-5 pollen sacs. Seed cones maturing and opening in 2 years, persistent to 20 years, oblong; scales persistent, 25-45, valvate, ± peltate, thick and woody. Seeds 3-9 per scale, lenticular, subequally 2-winged; cotyledons (3-)4(-6). x = 11" (1).

For the species: "Trees to 90 m; trunk to 11 m diam.; crown conic and monopodial when young, narrowed and somewhat rounded in age. Bark reddish brown, to ca. 60 cm thick, fibrous, ridged and furrowed. Branches generally horizontal to downward-sweeping with upturned ends. Leaves generally with stomates on both surfaces, the free portion to ca. 15 mm. Pollen cones nearly globose to ovoid, 4-8 mm. Seed cones 4-9 cm. Seeds 3-6 mm. 2n = 22" (1).

Range

USA: California: at 900-2700 m in mixed montane coniferous forests, in isolated groves along the western foothills of the Sierra Nevada (1). The species has been planted throughout Europe since 1853, and is an especially popular ornamental in the U.K., where the largest specimen (45 m tall and 260 cm dbh) grows at Leod Castle north of Inverness (2).

Big Tree

The General Sherman tree: height 83.6 m, dbh 825 cm, crown spread 33 m, located in Sequoia National Park, CA. This tree also has the largest known stem volume, 1473.4 m³. The largest diameter is recorded for the General Grant tree in Kings Canyon National Park, CA, which is 885 cm dbh and 81.1 m tall. The second largest stem volume, 1376.6 m³, is in the Washington tree, and the tenth largest has a stem volume of approximately 1150 m³. It is perhaps worth noting that timber scaling data show at least one specimen of Sequoia sempervirens logged in the early 20th Century had a recorded stem volume of approximately 1540 m³ (3). The tallest known giant sequoia is a specimen 93.6 m tall measured Aug-1998 by Michael Taylor in the Redwood Mountain Grove, California (5).

The giant sequoia is often called the largest living thing on earth. That superlative is somewhat debatable for two reasons:

1. It is difficult to define "a single living thing" among a group (living things) where it is sometimes impossible to draw a clear line between the individual and the colony. For example, an entire mountainside may be covered with a stand of aspen trees (Populus tremuloides) that are genetically identical and physically connected with each other (i.e., a clone); such a stand could be called "a single living thing". Closer to home, taxonomically speaking, clumps of Sequoia sempervirens may also be composed of genetically identical stems. Even if we restrict the field to identifiable single individual organisms, there are individuals of Ficus religiosa reported from India and Southeast Asia that sprawl over areas of many hectares; although a direct comparison has not been made, industrious searching might turn up an individual larger than any Sequoiadendron. At this time, though, the largest documented Ficus that I have heard of, is a banyan (F. benghalensis) in Uttar Pradesh, India, that supposedly covers 2.1 ha (3).

2. A large tree is not alive in the sense that you or I are alive. The foliage and the outer surface of the tree (technically, its inner bark, cambium and sapwood) are composed wholly or in part of living cells. However, the bark and most of the wood (xylem) are dead. In this sense a tree is a little bit like a coral -- we see the living skin of tissue over a dead framework that the tree has built up over the centuries of its growth. Most biologists overlook this point and treat the entire tree, living tissue and dead wood, as "live biomass." In practice, it is extremely difficult to measure how much of a tree is actually living tissue, and I haven't heard of it being done for any large trees. In conclusion, the General Sherman tree has the largest stem volume and probably the largest total biomass of any known individual tree. However, a few colonial organisms, including a variety of plants and some fungi, may have greater cumulative living biomass.

Oldest

Crossdated ages of 3220 years (specimen D-21) and 3075 years (specimen D-23) collected by Andrew E. Douglass in 1919. These were stump counts (some of Douglass' samples are still in storage at the Laboratory of Tree-Ring Research; they weigh hundreds of pounds). Also, 3033 years for specimen CMC3 collected by Swetnam and Baisan (Brown 1996). The only species (again, referring only to non-clonal individuals) known to attain greater ages are Pinus longaeva and Fitzroya cupressoides.

Dendrochronology

Attracted early attention by Douglass and others; most extensively studied by Swetnam and colleagues, 1990s, who have assembled a very long fire history.

Ethnobotany

Observations

All wild Sequoia groves are protected and most are relatively easy to visit. Particularly impressive and accessible groves are found in Yosemite, Sequoia and Kings Canyon National Parks; of these the most popular, and among the largest, is the Giant Forest in Sequoia National Park (2). The President, shown here, can be seen on the Congress Trail in the Giant Forest. It was originally (in 1923) called the Harding Tree, an appellation that fell from popularity along with the late President.

Remarks

The genus is named for Sequoia, the generic name of coast redwood, and the Greek DENDROS, tree (1). The tree was discovered in 1833 by a hunter who happened to wander into what is now the North Grove at Calaveras State Park; this has since become the most-visited of all the groves, thanks to easy access (4). Although it attracted immediate popular attention, the species went unnamed for 20 years. In 1852 specimens were received by Albert Kellogg of the California Academy of Sciences, who in May 1855 finally published it as Taxodium giganteum Kellogg and Behr. This was the fifth validly published name, however. The first name had been assigned on the basis of material collected (in the Calaveras grove) in summer 1853 by William Lobb, who was directed to the tree by Kellogg. Lobb dashed back to England, arriving 15 December 1853, and within two weeks the species was published by botanist John Lindley as Wellingtonia gigantea, named in honor of Arthur Wellesley, Duke of Wellington. In fact this name was invalid, Wellingtonia having been described in 1840 for a plant in the Sabiaceae, but this was not realized at the time. Lindley's publication triggered a storm of protest from American botanists who were outraged that the world's largest tree had been named for an English war hero by a botanist who had never seen the tree. The Americans promptly published a spate of invalid names. The French (always ready to irritate the English) then intervened in the person of of Joseph Decaisne, who in 1854 published the species as Sequoia gigantea, a plausible assignment that ultimately won acceptance by British botanists. Thereafter Wellingtonia slowly disappeared from the literature. Unfortunately, Sequoia gigantea was an invalid name, having been previously used by Endlicher to describe a horticultural variety of the coast redwood, and this problem was not satisfactorily resolved until the American John T. Buchholz described Sequoiadendron in 1939. Buccholz' name was not a popular choice, and was widely criticized by the old guard of California botanists, but his arguments--based on substantial differences in the development of Sequoia and Sequoiadendron seed cones--have subsequently won general acceptance (2).

Redwood, including Sequoiadendron giganteum and Sequoia sempervirens, is the state tree of California (1).

Citations

(1) Watson, Frank D. at the Flora of North America web site.
(2) Hartesveldt et al. 1975.
(3) E-mail communication, Robert Van Pelt, 29-Jul-1999.
(4) Flint, W.D. 1987. To find the biggest tree. Sequoia Natural History Association. 116 pp. (5) Telephone communication 14-Nov-1998 from Robert Van Pelt, who measured these trees in November 1998.