Thuja occidentalis

Linnaeus 1753

Common names

Northern white-cedar, thuier cèdre, cèdre-thuya occidental (Chambers 1993), eastern whitecedar, American or eastern arborvitae.

Taxonomic notes

Description

Trees to 15(38) m tall and 90(180) cm dbh, "stunted or prostrate in harsh environments; trunk sometimes divided into 2-3 secondary stems, often reproducing by layering or forming erect, rooted branches from fallen trunks; crown conical. Bark reddish brown or grayish brown, 6-9 mm thick, fibrous, fissured. Leaves of branchlets (1.5)3-5 mm, acute, dull yellowish green on both surfaces of branchlets. Pollen cones 1-2 mm, reddish. Seed cones ellipsoid, (6)9-14 mm, brown; fertile scales usually 2 pairs, each minutely mucronate. Seeds ca. 8 per cone, 4-7 mm (including wings), reddish brown. 2n = 22" (Chambers 1993).

Range

Canada: Manitoba, Ontario, Québec; Prince Edward Island, New Brunswick, Nova Scotia; USA: Minnesota, Michigan, Wisconsin, Illinois, Indiana, Ohio, Kentucky, Tennessee, North Carolina, Virginia, West Virginia, Maryland, Pennsylvania, New York, Connecticut, Massachusetts, Vermont, New Hampshire, Maine; at 0-900 m elevation on mostly calcareous substrates, neutral to basic swamps, shores of lakes and rivers, uplands, cliffs, and talus. Isolated stands occur north and east of its general range in Canada (to 51° 31' N latitude in Ontario, 50° N in Quebec). In the United States south of the Great Lakes and in southern New England, it occurs locally in scattered stands and is rare or extirpated at numerous former sites. In some areas, heavy winter browsing by deer greatly reduces reproductive success through elimination of seedlings or saplings (Chambers 1993). See also Thompson et al. (1999).

Big tree

Diameter 175 cm, height 34 m, crown spread 13 m, located in Leelanau County, MI (American Forests 1996).

Oldest

"The oldest living cedar that we have lives on a cliff face and it germinated in 952 A.D. (i.e. 1051 years old). This was determined from a cross-dated tree-ring count back to 1039 A.D. plus an estimated 87 years lost from the pith area. The oldest dead white cedar I've found had a tree-ring count of 1,653 years. This is a pith date from the base. Another white cedar with a ring count of 1,567 years was estimated to be missing 323 rings from its base, thus an estimated age of 1,890 years" (Kelly and Larson 1997, and P.E. Kelly e-mail 2002.11.15).

Dendrochronology

Besides the work by Kelly and Larson (1997), a variety of other studies are indexed on the Bibliography of Dendrochronology.

Ethnobotany

Most species of Thuja are commonly known as arborvitae, Latin for "tree of life." In 1536, the French captain Jacques Cartier was on his second voyage of discovery to Canada. He sailed up the St. Lawrence River with a crew of 110 seamen and a pair of Huron boys he had picked up on his first voyage two years earlier. After months at sea without fresh fruit or vegetables, the crew was suffering from scurvy, a potentially fatal vitamin C deficiency. On his way upriver, he left the two natives in their home village, expecting neither to survive the serious scurvy attack, which had beset them during the Atlantic crossing. Later Cartier returned to the village and found the two boys fully recovered. He appealed to the natives to show him how the cure was achieved, and was shown how to chop and boil the foliage of Thuja occidentalis to extract the medicine that would cure the crew. He named the plant "tree of life" and brought samples home, making it the first North American tree to be introduced to Europe (Klingaman 2002; Wikipedia, 2009.01.23).

Henry David Thoreau, in "The Allagash and East Branch," writes extensively about how native Americans in Maine used this species. These uses included cordage (the bark), mattresses (the boughs), and roofing (shingles), along with many lesser uses.

Thuja occidentalis is widely utilized in ornamental silviculture and has more than 120 named cultivars (Chambers 1993).

Observations

Remarks

Citations

Kelly, P.E. and D.W. Larson. 1997. Effects of rock climbing on populations of presettlement eastern white cedar (Thuja occidentalis) on cliffs of the Niagara Escarpment, Canada. Conservation Biology 11(5): 1125-1132.

Klingaman, Gerald. 2002. Plant of the Week: Eastern Arborvitae. http://www.arhomeandgarden.org/plantoftheweek/articles/Eastern_Arborvitae.htm, accessed 2009.01.23.

See also

Burns and Honkala (1990).

Farjon (2005).

Prasad and Iverson (1999).