Thuja occidentalis

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Thuja occidentalis
Thuja occidentalis.jpg
Leaves and immature cones
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Cupressaceae
Genus: Thuja
T. occidentalis
Binomial name
Thuja occidentalis
Thuja occidentalis range map.png
Natural range

Thuja occidentalis, also known as northern white cedar, [1] eastern white cedar, [2] or arborvitae, [2] [3] is an evergreen coniferous tree, in the cypress family Cupressaceae, which is native to eastern Canada and much of the northcentral and northeastern United States. [3] [4] It is widely cultivated as an ornamental plant.



The species was first described by Carl Linnaeus in 1753. There are over 30 synonyms in Kew's Plants of the World Online database. [5]

Common names

Additional common names include swamp cedar, [3] American arborvitae, [4] and eastern arborvitae. [4] The name arborvitae is particularly used in the horticultural trade in the United States. It is Latin for "tree of life" - due to the supposed medicinal properties of the sap, bark, and twigs. [6] It is sometimes called white-cedar (hyphenated) or whitecedar (one word) [4] to distinguish it from Cedrus , a distantly related genus of trees also known as cedars. [7]


Unlike the closely related western red cedar (Thuja plicata), northern white cedar is only a small or medium-sized tree, growing to a height of 15 m (49 ft) tall with a 0.9 m (3.0 ft) trunk diameter, exceptionally to 38 metres (125 ft) tall and 1.8 metres (5.9 ft) diameter. [8] The tree is often stunted or prostrate in less favorable locations. The bark is red-brown, furrowed and peels in narrow, longitudinal strips. Northern white cedar has fan-like branches and scaly leaves. The foliage forms in flat sprays with scale-like leaves 3–5 millimetres (18316 in) long.

The seed cones are slender, yellow-green, ripening to brown, 9–14 millimetres (38916 in) long and 4–5 millimetres (532316 in) broad,[ citation needed ] with 6-8 overlapping scales. They contain about 8 seeds each. [8] The branches may take root if the tree falls. [4]


Northern white cedar is native to an area in the southern part of eastern Canada and the adjacent part of the northern United States. It extends from southeastern Manitoba east throughout the Great Lakes region and into Ontario, Québec, New York, Vermont, New Hampshire, Maine, Prince Edward Island, New Brunswick, and Nova Scotia. There are isolated populations in west-central Manitoba, and to the south in Massachusetts, Connecticut, Ohio, and Illinois and in the Appalachian Mountains of Kentucky, Tennessee, North Carolina, Pennsylvania, Maryland, Virginia, and West Virginia. [4] In Canada, its range reaches the Arctic treeline and the southern tip of Hudson Bay. It grows mainly in places with cooler summers, with an average temperature of 16 to 22 °C (61 to 72 °F) in July, and a shorter growing season, from 90 to 180 days. [9]


A swamp along the Superior Hiking Trail in November with white cedars (left) and other trees and shrubs Superior Hiking Trail boardwalk.jpg
A swamp along the Superior Hiking Trail in November with white cedars (left) and other trees and shrubs

Northern white cedar grows naturally in wet forests, being particularly abundant in coniferous swamps where other larger and faster-growing trees cannot compete successfully. It also occurs on other sites with reduced tree competition, such as cliffs. Although not currently listed as endangered, wild white cedar populations are threatened in many areas by high deer numbers; deer find the soft evergreen foliage a very attractive winter food and strip it rapidly. The largest known specimen is 34 m (112 ft) tall and 175 cm (69 in) diameter, on South Manitou Island within Leelanau County, Michigan.[ citation needed ] Northern white cedar can be a very long-lived tree in certain conditions, with notably old specimens growing on cliffs where they are inaccessible to deer and wildfire; in 2008, the oldest known living specimen was 1,141 years old, [10] but a dead specimen with 1,653 growth rings has been found. [11] Despite their age, these very old trees are small and stunted due to the difficult growing conditions. These individuals' long life spans have been attributed to their slow growth and their ability to survive when different sections of the tree are damaged or killed. [12] The Witch Tree, a T. occidentalis growing out of a cliff face on Lake Superior in Minnesota, was described by the French explorer Sieur de la Verendrye as being a mature tree in 1731; it is still alive today.

Old trees growing on a rock ledge in Potawatomi State Park, Wisconsin Something out of nothing 2.jpg
Old trees growing on a rock ledge in Potawatomi State Park, Wisconsin

Specimens found growing on cliff faces in southern Ontario are the oldest trees in Eastern North America and all of Canada, growing to ages in excess of 1,653 years. [4]


Thuja occidentalis is a tree with important uses in traditional Ojibwe culture. Honored with the name Nookomis Giizhik ("Grandmother Cedar"), the tree is the subject of sacred legends and is considered a gift to humanity for its myriad uses, among them crafts, construction, and medicine. [13] It is one of the four plants of the Ojibwe medicine wheel, associated with the north. The foliage is rich in Vitamin C and is believed to be the annedda which cured the scurvy of Jacques Cartier and his party in the winter of 1535–1536. [9] Due to the presence of the neurotoxic compound thujone, internal use can be harmful if used for prolonged periods or while pregnant.[ citation needed ] It is commercially used for rustic fencing and posts, lumber, poles, shingles, and in the construction of log cabins. [9] It is the preferred wood for the structural elements, such as ribs and planking, of birchbark canoes and the planking of wooden canoes. [14]

The essential oil within the plant has been used for cleansers, disinfectants, hair preparations, insecticides, liniment, room sprays, and soft soaps. There are some reports that the Ojibwa made a soup from the inner bark of the soft twigs. Others have used the twigs to make teas to relieve constipation and headache. [14]


A grove of a columnar ornamental variety in Powsin Botanical Garden, Warsaw, Poland Poland. Warsaw. Powsin. Botanical Garden 097.jpg
A grove of a columnar ornamental variety in Powsin Botanical Garden, Warsaw, Poland

Thuja occidentalis is widely used as an ornamental tree, particularly for screens and hedges, in gardens, parks and cemeteries. Over 300 cultivars exist, showing great variation in colour, shape and size, with some of the more common ones being: 'Degroot's Spire', 'Ellwangeriana', 'Hetz Wintergreen', 'Lutea', 'Rheingold', 'Smaragd' (a.k.a. 'Emerald Green'), 'Techny', and 'Wareana'. It was introduced into Europe as early as 1540.[ citation needed ] The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit: 'Danica', [15] 'Holmstrup', [16] 'Rheingold', [17] and 'Smaragd'. [18]

Related Research Articles


Thuja is a genus of coniferous trees in the Cupressaceae. There are five species in the genus, two native to North America and three native to eastern Asia. The genus is monophyletic and sister to Thujopsis. Members are commonly known as arborvitaes, thujas or cedars.

<i>Cryptomeria</i> Species of conifer in the family Cupressaceae

Cryptomeria is a monotypic genus of conifer in the cypress family Cupressaceae, formerly belonging to the family Taxodiaceae. It includes only one species, Cryptomeria japonica. It used to be considered by some to be endemic to Japan, where it is known as Sugi. The tree is called Japanese cedar or Japanese redwood in English.

<i>Cupressus nootkatensis</i>

Cupressus nootkatensis is a species of trees in the cypress family native to the coastal regions of northwestern North America. This species goes by many common names including: Nootka cypress, yellow cypress, Alaska cypress, Nootka cedar, yellow cedar, Alaska cedar, and Alaska yellow cedar. The specific epithet "nootkatensis" is derived from its discovery by Europeans on the lands of a First Nation of Canada, those lands of the Nuu-chah-nulth people of Vancouver Island, British Columbia, who were formerly referred to as the Nootka.

<i>Thuja plicata</i> Species of conifer in the family Cupressaceae

Thuja plicata, commonly called western red cedar or Pacific red cedar, giant arborvitae or western arborvitae, giant cedar, or shinglewood, is a species of Thuja, an evergreen coniferous tree in the cypress family Cupressaceae native to western North America. It is not a true cedar of the genus Cedrus.


Platycladus is a monotypic genus of evergreen coniferous tree in the cypress family Cupressaceae, containing only one species, Platycladus orientalis, also known as Chinese thuja, Oriental arborvitae, Chinese arborvitae, biota or Oriental thuja. It is native to northeastern parts of East Asia and North Asia, but is also now naturalised as an introduced species in other regions of the Asian continent.

<i>Pieris</i> (plant) Genus of flowering plants in the heath family Ericaceae

Pieris is a genus of seven species of shrubs in the family Ericaceae, native to mountain regions of eastern and southern Asia, eastern North America and Cuba. Known commonly in North America as andromedas or fetterbushes, they are broad-leaved evergreen shrubs growing to 1–6 metres tall and 3–10 ft (0.9–3.0 m) wide. The leaves are spirally arranged, often appearing to be in whorls at the end of each shoot with bare stretches of shoot below; they are lanceolate-ovate, 2–10 cm (0.8–3.9 in) long and 1.0–3.5 cm (0.4–1.4 in) broad, leathery textured, and with an entire or serrated margin. The young leaves in spring are typically brightly coloured. The flowers are bell-shaped, 5–15 mm (0.2–0.6 in) long, white or pink, and arranged in racemes 5–12 cm (2.0–4.7 in) long. The fruit is a woody capsule which splits into five sections to release the numerous small seeds.

<i>Abies nordmanniana</i>

Abies nordmanniana, the Nordmann fir or Caucasian fir, is a fir indigenous to the mountains south and east of the Black Sea, in Turkey, Georgia and the Russian Caucasus. It occurs at altitudes of 900–2,200 m on mountains with precipitation of over 1,000 mm.

<i>Dasiphora fruticosa</i> Species of flowering plant in the rose family Rosaceae

Dasiphora fruticosa is a species of hardy deciduous flowering shrub in the family Rosaceae, native to the cool temperate and subarctic regions of the northern hemisphere, often growing at high altitudes in mountains. Dasiphora fruticosa is a disputed name, and the plant is still widely referenced in the horticultural literature under its synonym Potentilla fruticosa. Common names include shrubby cinquefoil, golden hardhack, bush cinquefoil, shrubby five-finger, tundra rose, and widdy.

Blue spruce

The blue spruce, green spruce, white spruce, Colorado spruce, or Colorado blue spruce, with the Latin (scientific) name Picea pungens, is a species of spruce tree. It is native to North America, and is found in growing zones 1 through 7. Its natural range extends from northern New Mexico through Colorado and Utah to Wyoming and into Alberta and British Columbia, but it has been widely introduced elsewhere and is used as an ornamental tree in many places far beyond its native range. The blue spruce has blue-green coloured needles and is a coniferous tree.

<i>Calycanthus</i> Genus of flowering plants in the Magnoliid family Calycanthaceae

Calycanthus, called sweetshrub, is a genus of flowering plants in the family Calycanthaceae, endemic to North America. The genus includes two to four species depending on taxonomic interpretation; two are accepted by the Flora of North America.

White cedar may refer to several different trees:

<i>Cornus sericea</i>

Cornus sericea, syn. C. stolonifera, Swida sericea, red osier or red-osier dogwood, is a species of flowering plant in the family Cornaceae, native throughout northern and western North America from Alaska east to Newfoundland, south to Durango and Nuevo León in the west, and Illinois and Virginia in the east. It has sometimes been considered a synonym of the Asian species Cornus alba. Other names include red brush, red willow, redstem dogwood, redtwig dogwood, red-rood, American dogwood, creek dogwood, and western dogwood.

<i>Lavandula angustifolia</i> Species of plant

Lavandula angustifolia, formerly L. officinalis, is a flowering plant in the family Lamiaceae, native to the Mediterranean. Its common names include lavender, true lavender or English lavender ; also garden lavender, common lavender, and narrow-leaved lavender.

<i>Calocedrus decurrens</i>

Calocedrus decurrens, with the common names incense cedar and California incense-cedar, is a species of conifer native to western North America. It is the most widely known species in the genus, and is often simply called 'incense cedar' without the regional qualifier.

<i>Cupressus cashmeriana</i>

Cupressus cashmeriana, the Bhutan cypress, or Kashmir cypress, is a species of evergreen conifer native to the eastern Himalaya in Bhutan and adjacent areas of Arunachal Pradesh in northeastern India. It is also introduced in China and Nepal. It grows at moderately high altitudes of 1,250–2,800 metres (4,100–9,190 ft).

<i>Didymascella thujina</i>

Didymascella thujina is an ascomycete fungus in the family Helotiaceae. D. thujina causes cedar leaf blight, a leaf disease, on western red cedar and white cedar (T. occidentalis).

Coniferous swamp

Coniferous swamps are forested wetlands in which the dominant trees are lowland conifers such as northern white cedar. The soil in these swamp areas is typically saturated for most of the growing season and is occasionally inundated by seasonal storms or by winter snow melt.

<i>Acer palmatum</i>

Acer palmatum, commonly known as Japanese maple, palmate maple, or smooth Japanese maple, is a species of woody plant native to Japan, Korea, China, eastern Mongolia, and southeast Russia. Many different cultivars of this maple have been selected and they are grown worldwide for their large variety of attractive forms, leaf shapes, and spectacular colors.

<i>Crassula ovata</i>

Crassula ovata, commonly known as jade plant, lucky plant, money plant or money tree, is a succulent plant with small pink or white flowers that is native to the KwaZulu-Natal and Eastern Cape provinces of South Africa, and Mozambique; it is common as a houseplant worldwide. Much of its popularity stems from the low levels of care needed; the jade plant requires little water and can survive in most indoor conditions. It is sometimes referred to as the money tree; however, Pachira aquatica also has this nickname.

T. occidentalis can refer to a few different species. The specific epithet occidentalis means 'western.'


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  6. Thuja, American Cancer Society, last revised 6/19/2007. available online
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  12. Larson, D.W. (2001). "The paradox of great longevity in a short-lived tree species". Experimental Gerontology. 36 (4–6): 651–673. doi:10.1016/S0531-5565(00)00233-3. ISSN   0531-5565. PMID   11295506. S2CID   24297929.
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