Mature sun foliage from the canopy of an old-growth tree [C.J. Earle].
Sequoia , like all of the Cupressaceae, is cladoptosic: dead foliage falls with the accompanying shoot, rather than as individual leaves [Dr. Linda B. Brubaker].
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Sequoia sempervirens
(D. Don) Endlicher 1847
Common NamesCoast redwood, redwood, California redwood (4), coastal sequoia, palo colorado.Taxonomic notesSyn: Taxodium sempervirens D. Don in Lambert 1824 (5); Sequoia sempervirens (Lambert) Endlicher (3). It is the sole species in Sequoia Endlicher 1847. Described varieties include adpressa, glauca, nana pendula, pendula and prostrata (1).DescriptionTree to 60-100(110) m tall and 300-460(900) cm dbh. Trunk much enlarged and buttressed at the base and often with rounded swellings or burls, slightly tapering. Crown crown conic and monopodial when young, narrowed conic in age, irregular and open. Bark red-brown, to ca. 35 cm thick, tough and fibrous, deeply furrowed into broad, scaly ridges; inner bark cinnamon-brown. Branches downward sweeping to slightly ascending. Twigs slender, dark green, forking in a plane, ending in a scaly bud. Leaves 1-30 mm, generally with stomates on both surfaces, the free portion to 30 mm, those on leaders, ascending branchlets, and fertile shoots divergent to strongly appressed, short-lanceolate to deltate, those on horizontally spreading to drooping branchlets mostly linear to linear-lanceolate, divergent and in 2 ranks, with 2 prominent, white abaxial stomatal bands. Pollen cones nearly globose to ovoid, 2-5 mm, borne singly on short terminal or axillary stalks. Female cones 12-35 mm long, elliptical, reddish-brown, with many flat, short-pointed scales; pendant at end of leafy twig; maturing in one season; with 2-5 seeds per scale, light brown, 2-winged. Seeds flattened, 3-6 mm, leathery. 2 n = 66 (4, 5).The genus Sequoia has been described as follows: "Trees giant, evergreen. Branchlets terete, with obvious annual growth constrictions. Leaves alternate, mostly in 2 ranks. Adult leaves linear or linear-lanceolate to deltate, generally flattened, divergent to strongly appressed; abaxial glands absent. Pollen cones with 6-12 sporophylls, each sporophyll with 2-6 pollen sacs. Seed cones maturing and opening in 1 season, oblong to globose; scales persistent, 15-30, valvate, ± peltate, thick and woody. Seeds 2-7 per scale, lenticular, narrowly 2-winged; cotyledons 2(-4). x = 11" (5). RangeUSA: SW Oregon and NW California, confined to coastal areas (within 60 km of the sea) experiencing a great deal of fog; at elevations generally below 300 m, occasionally to 1000 m. Mostly found in alluvial soils, where it forms pure stands or occurs with Pseudotsuga menziesii , Chamaecyparis lawsoniana , or other local conifers (4, 5).Big TreeThe largest volume tree is the Del Norte Titan, discovered June 1998 in Jedediah Smith Redwoods State Park, California, by Steve Sillett and Michael Taylor. This tree has an estimated stem volume of 1044.7 cubic meters and is 93.57 m tall with a dbh of 7.22 m.The coast redwood is probably the tallest tree on earth, although one occasionally hears of extraordinarily tall eucalypts in Western Australia, and during historical times there have been Douglas-firs ( Pseudotsuga menziesii ) known to be taller than any coast redwoods now living. However, it is quite likely that the tallest coast redwoods were early victims of the axe, so it is difficult to say if the redwoods was the tallest of conifers during early historical time. The following table, provided by Michael Taylor (7), provides summary information on all coast redwoods known to be over 110 meters tall, as measured by direct tape drop or Criterion 400 laser surveyor.
Other likely 110+ meter coast redwoods have been found, but an accurate measurement of height has not been determined yet so they are not on list. OldestA ring-counted age of 2200 years for a specimen from N California collected by Fritz (8). This was probably a stump count.DendrochronologyEthnobotanyObservationsThe species is well protected in its native range and can easily be seen in California's Redwood National Park, Muir Woods National Monument, and a long chain of State Parks of which some of the more noteworthy are, from north to south, Jedediah Smith Redwoods, Prairie Creek Redwoods, Humboldt Redwoods, and Big Basin Redwoods.RemarksThe genus is widely thought to be named for Sequoyah, also known as George Guess, inventor and publisher of the Cherokee alphabet. Endlicher was also a philologist, so he likely knew of Sequoyah's achievements. Unfortunately, Endlicher's writings give no clue to the etymology of Sequoia, and some very eminent botanists have proposed plausible alternatives. Asa Gray, for instance, thought it came from the Latin sequi, 'following', since it is the sole living representative of a sizable group of extinct plants (10).Redwood is one of the few vegetatively reproducing conifers, readily regenerating from stump sprouts in the wake of a major disturbance (typically fire). One peculiar consequence of this is the occurrence of 'white redwoods' (see photo), which are trees that originate as root sprouts and are competely nonphotosynthetic, deriving all of their carbohydrate from the roots of their photosynthetic associates (which are not necessarily related, as root grafting is common between redwoods). White redwoods are found only in old-growth forests, where the overstory biomass of photosynthetic redwoods is colossal (redwood forests have the highest aboveground biomass loadings in the world) and the white trees are generally less than 3 meters tall. However, white redwoods up to 20 meters tall are known to exist. The tree in the photograph is about 10 m tall. At the time of the photograph, the new year's foliage had not emerged; trees clad in fresh foliage are snow-white. Redwood is the only naturally occurring hexaploid conifer. Redwoods (Sequoia sempervirens and Sequoiadendron giganteum) are the state tree of California (5). The sequoias (including Sequoia and Sequoiadendron ) were another group, like Metasequoia, first known from the fossil record, although fossil material was not formally named until Steinhauera Presl 1838, ten years after Lambert described this species as Taxodium sempervirens (10). Citations(1) Silba 1986.(2) Elias 1987. (3) Peattie 1950. (4) Little 1980. (5) Watson, Frank D. at the Flora of North America web site. (6) Burns & Honkala 1990. (7) E-mail communication from Michael Taylor, 26-Jul-1998. (8) Brown 1996. (9) This illustration is from Dr. Van Pelt's forthcoming book on giant trees of western North America, to be published by the University of Washington Press. (10) Hartesveldt et al. 1975. See also: |
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