Thuja occidentalis
Thuja occidentalis
Safety & Hazards
The essential oil in this plant contains thujone. Thujone is a GABA receptor antagonist which allows neurons to fire more easily. In larger doses this can cause muscle spasms and convulsions, and can also be toxic to brain, kidney, and liver cells. There has been a lot of negative press regarding thujone, particularly in the mid 19th century when thujone was reported to be more dangerous than alcohol - since shown to be exaggerated; and reports in the 1970’s that it might have a similar effect on the brain to THC (found in cannabis) – since found to be incorrect. Thujone is probably best known for its use in the alcoholic drink ‘Absinthe’. It is also found in the essential oils of many other plants that are used in herbal medicines and foods, including Arborvitae (Thuja species), some Junipers (Juniperus species), Wormwoods (especially Artemisia absinthium) and Sage (Salvia officinalis). There are some legal restrictions in various countries on the quantity of thujone that can be added to foods and drinks and these vary between countries. Side effects from consuming thujone can include sleeplessness and anxiety but, unless the pure essential oil is used, the quantity of thujone found in plants is well within safety levels. Pregnant women, however, may be advised to restrict their use of thujone-containing plants.
Botanical Description
Thuja occidentalis is an evergreen tree with a conical crown; it usually grows up to 15 metres tall, exceptionally to 38 metres, though it is stunted or prostrate in harsh environments. The straight, cylindrical bole is up to 90cm in diameter (exceptionally to 180cm) and is sometimes divided into 2 - 3 secondary stems. The tree often reproduces by means of layering or by forming erect, rooted branches from fallen trunks[ 270 Title Flora of N. America Publication Author Website http://flora.huh.harvard.edu/fna/ Publisher Year 0 ISBN Description An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses. ]. Thuja occidentalis is an important timber tree, the wood being used especially for applications requiring decay resistance. It also has a range of medicinal uses, was a traditional food of the native N. Americans and has a range of other uses. The tree is often grown as a timber crop in temperate regions, and is widely utilized as an ornamental - it has more than 120 named cultivars. It was probably the first North American tree introduced into Europe (ca 1566)[ 270 Title Flora of N. America Publication Author Website http://flora.huh.harvard.edu/fna/ Publisher Year 0 ISBN Description An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses. ]. Thuja occidentalis is extremely widespread and in some parts of its range is increasing by invasion of abandoned farmland. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[ 338 Title IUCN Red List of Threatened Species Publication Author Website http://www.iucnredlist.org/ Publisher Year 0 ISBN Description A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat. ].