Thuja occidentalis, also known as听northern white-cedar,听eastern white-cedar,听辞谤听补谤产辞谤惫颈迟补别,听is an听听听, in the cypress family听, which is听听to eastern Canada and much of the north-central and northeastern United States.听It is widely cultivated as an ornamental plant. It is not to be confused with听听(eastern red cedar).
Common names
Its additional common names include听swamp cedar,听American arborvitae,听and听eastern arborvitae.听The name arborvitae is particularly used in the听听trade in the United States; it is听听for 'tree of life' 鈥� due to the supposed medicinal properties of the sap, bark, and twigs.听It is sometimes called white-cedar (hyphenated) or whitecedar (one word)听to distinguish it from听, the听.
Description
Unlike the closely related听听(Thuja plicata), northern white cedar is only a small or medium-sized tree, growing to a height of 15听m (49听ft) tall with a 0.9听m (3.0听ft) trunk diameter, exceptionally to 38 metres (125听ft) tall and 1.8 metres (5.9听ft) diameter.听The tree is often stunted or prostrate in less favorable locations. The听听is red-brown, furrowed and peels in narrow, longitudinal strips. Northern white cedar has fan-like branches and scaly leaves. The听听forms in flat sprays with scale-like听听3鈥�5 millimetres (1鈦�8鈥�3鈦�16听in) long.
The听听are slender, yellow-green, ripening to brown,听9鈥�14 millimetres (3鈦�8鈥�9鈦�16听in) long and听4鈥�5 millimetres (5鈦�32鈥�3鈦�16听in) broad,[]听with six to eight overlapping scales. They contain about eight seeds each.听The branches may take root if the tree falls.
Taxonomy
The species was first described by听听in 1753. Over 30 synonyms are listed in听's听听database.
Distribution
Northern white cedar is听听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听,听,听,听,听,听,听,听, and听. Isolated populations occur in west-central Manitoba, and to the south in听,听,听, and听听and in the听听of听,听,听,听,听,听, and听.听In Canada, its range reaches the听听and the southern tip of听. It grows mainly in places with cooler summers, with a typical temperature of 16 to 22听掳C (61 to 72听掳F) in July, and a shorter growing season, from 90 to 180 days.
Ecology
Northern white cedar grows naturally in wet forests, being particularly abundant in听, where other larger and faster-growing trees cannot compete successfully. It also occurs on other sites with reduced tree competition, such as听. Although not currently listed as endangered, wild white cedar populations are threatened in many areas by high听听numbers; deer find the soft evergreen foliage a very attractive winter food and strip it rapidly. The largest known specimen is 34听m (112听ft) tall and 175听cm (69听in) diameter, on听听within听.[]听Northern white cedars can be very long-lived trees in certain conditions, with notably old specimens growing on cliffs where they are inaccessible to deer and听. As of 2008, the oldest known living specimen was 1,141 years old,听but a dead specimen with 1,653 growth rings has been found.听Despite their age, these very old trees are small and stunted due to the difficult growing conditions. These individuals' long lifespans have been attributed to their slow growth and their ability to survive when different sections of the tree are damaged or killed.听The听, a听T. occidentalis听growing out of a cliff face on听听in听, was described by the听听explorer听听as being a mature tree in 1731; it is still alive today.
Specimens found growing on cliff faces in southern Ontario are the oldest trees in 听and all of Canada, having achieved ages in excess of 1,653 years.
Uses
Thuja occidentalis听is commercially used for rustic fencing and posts, lumber, poles, shingles, and in the construction of听.听It is the preferred wood for the structural elements, such as ribs and planking, of听听听and the planking of wooden听.
The essential oil within the plant has been used for听,听, hair preparations,听,听, room sprays, and soft soaps. The Ojibwa reportedly made a soup from the inner bark of the soft twigs. Others have used the twigs to make teas to relieve听听and听.
Eastern white cedar -听听- is a popular听听used in both residential and commercial landscapes.
Thuja occidentalis听has important uses in traditional听听culture. Honoured with the name听Nookomis Giizhik听(Grandmother Cedar), the tree is the subject of sacred legends and is considered a gift to humanity for its myriad of uses, among them crafts, construction, and medicine.听It is one of the four plants of the Ojibwe听, associated with the north. The foliage is rich in听听and is believed to be the听, which cured the听听of听听and his party in the winter of 1535鈥�1536.听Due to the presence of the neurotoxic compound听, internal use can be harmful if used for prolonged periods or while pregnant.[]
Cultivation
T. occidentalis听is widely used as an听, particularly for screens and听, in gardens, parks, and cemeteries. Over 300听听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' (or 'Emerald Green'), 'Techny', and 'Wareana'. It was introduced into听听as early as 1540.[]听These cultivars have gained the听's听:
- 'Danica',
- 'Golden Tuffet'
- 'Holmstrup',
- 'Rheingold',
- 'Smaragd'.