Cupressaceae FAMILY Least Concern

Thuja plicata

Edibility

2/5

Medicinal

2/5

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 plicata is an evergreen tree with a conical crown; it usually grows up to 50 metres tall, exceptionally to 75 metres, though it can be stunted in harsh environments. The straight, cylindrical bole is up to 200cm in diameter (exceptionally to 500cm), and is often buttressed at the base. Thuja plicata is an important commercialy harvested timber tree, its soft but extremely durable wood being valued for construction etc. The tree also has a wide range of traditional uses as a food, medicine and source of materials. The plant is cultivated as a timber crop in N. America and Europe, and is also commonly grown as an ornamental in parks and gardens - many cultivars have been developed[ 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. ]. Despite extensive logging, the extensive range and abundance of Thuja plicata makes it ineligible for any threatened category. 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. ].

Habitat & Origin

Origintemperate

Native RangeWestern N. America - British Columbia to California.

HabitatGrows singly and in small groves, on various substrates, in moist to swampy soils, usually in shady forests; at elevations from sea-level to 1,500 metres[ 60 Title Vascular Plants of the Pacific Northwest. Publication Author Hitchcock. C. L. Publisher University of Washington Press Year 1955 ISBN - Description A standard flora for Western N. America with lots of information on habitat etc. Five large volumes, it is not for the casual reader. , 82 Title Manual of the Trees of N. America. Publication Author Sargent. C. S. Website http://www.biodiversitylibrary.org/ Publisher Dover Publications Inc. New York. Year 1965 ISBN 0-486-20278-X Description Two volumes, a comprehensive listing of N. American trees though a bit out of date now. Good details on habitats, some details on plant uses. Not really for the casual reader. It can be downloaded from the internet. , 99 Title Plants in British Columbian Indian Technology. Publication Author Turner. N. J. Publisher British Columbia Provincial Museum Year 1979 ISBN 0-7718-8117-7 Description Excellent and readable guide. , 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. ].