Scientific Name(S): Taxus bacatta L. and T. cuspidata Sieb. and Zucc. The native species of the US, T. canadensis Marsh. is found throughout the eastern United States; other species found in North America include T. floridana Nutt. and the western or California yew, T. brevifolia Nutt. Family: Taxaceae
Common Name(S): Yew, ground hemlock
This common evergreen is found throughout woods and forests and is often used as an ornamental hedge bush. The trunk supports a crown of spreading branches with long, narrow, dark green shiny leaves. It is dioecious, with male and female flowers being produced on different trees. The ovoid seed is black and is surrounded by a red, fleshy covering called the aril. Yews flower in March and April.
The yew plant has been used to treat rheumatisms, liver and urinary tract conditions, and most recently to treat cancer cells.
The ingestion of the plant results in dizziness, dry mouth, mydriasis, and abdominal cramping. Rash and pale cyanotic skin may develop. It may eventually result in death.
The Celts coated their arrows with yew sap as a nerve toxicant. The alkaloid taxine has been used as an antispasmodic. A tincture of the leaves had been used to treat rheumatisms and liver and urinary tract conditions.
The entire plant, with the exception of the red, fleshy aril, contains approximately 19 taxane alkaloids, of which the best known is taxine. Other alkaloids (milossine, ephedrine), the glycoside taxicatin, paclitaxel and its derivatives, and pigments are found throughout the plant. Bristol-Myers Squibb recently received FDA approval to market paclitaxel (Taxol) as an antineoplastic agent for ovarian cancer, and concern has been raised regarding the environmental impact of debarking Pacific yew trees to harvest the drug. Consequently, methods have been developed to produce paclitaxel from precursors found in the leaves, twigs and needles of yews common in Europe and Asia, and others are attempting to synthesize paclitaxel from pinene, a common compound found in pine trees. Paclitaxel content varies from 0.00003% to 0.069% of the plant. The approved generic name, paclitaxel, was previously referred to as "taxol." Taxol is now the trademarked brand name for paclitaxel.
The yew has been used in herbal medicine for centuries. The plant is now considered to be of major medical importance, with one extract approved for its antineoplastic activity. Because it is one of the most common foundation plantings in North America, it is often associated with childhood and animal poisonings. All parts of the plant are toxic with the exception of the red fruit.
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