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Taxus brevifolia |
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Family: Taxaceae |
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Pacific Yew |
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The genus Taxus
is composed of 10 species native to North America [3], Central America [1] and
Eurasia [6]. The word taxus is the classical Latin name, from the Greek taxos. The word brevifolia means short leaf,
referring to the size of its needles, relative to the English yew (Taxus baccata L.). Recently, taxol,
an anti-cancer agent, has been isolated from the bark of Taxus brevifolia.
Other Common
Names:
Canadese taxus, Canadian yew, if a feuilles courtes, if du Canada, if
occidental, kanadensisk idegran, mountain mahogany, Oregon yew, Pacific yew,
pazifische eibe, tassi d'america, tasso americano, taxo americano, tejo
americano, western yew, westerse taxus, yew.
Distribution: Pacific yew is native
to the Pacific Coast region from southeast Alaska, south in western British
Columbia, western Washington, western Oregon and northern and central
California (including the Sierra Nevada). It is also grows in the Rocky
Mountain region from southeast British Columbia south to northwest Montana,
northern Idaho, eastern Washington and northeast Oregon.
The Tree: Pacific yew trees reach
heights of 50 feet, with diameters of 2 feet. The largest tree on record was 60
feet tall, with a diameter of 6 feet.
General Wood
Characteristics:
The wood from Pacific yew has a thin light tan sapwood, while the heartwood is
brown to bright orange. It is dense, very hard and strong, heavy and has a very
fine, straight and close grain with a fine texture. It has a high luster and
has no characteristic odor or taste.
Mechanical
Properties (2-inch standard)
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Compression |
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Specific gravity |
MOE GPa |
MOR MPa |
Parallel MPa |
Perpendicular MPa |
WMLa Kj/m3 |
Hardness N |
Shear MPa |
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Green |
0.60 |
6.83 |
69.6 |
32.1 |
7.17 |
139 |
5110 |
11.2 |
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Dry |
0.67 |
9.31 |
105 |
55.8 |
14.5 |
129 |
7120 |
15.4 |
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aWML = Work to maximum load.
Reference (153). |
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Drying and
Shrinkage
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Type of shrinkage |
Percentage of
shrinkage |
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0% MC |
6% MC |
20% MC |
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Tangential |
5.4 |
4.3 |
1.8 |
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Radial |
4.0 |
3.2 |
1.3 |
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Volumetric |
9.7 |
7.8 |
3.2 |
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References: (153, 192). |
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Kiln Drying
Schedulesa
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Conventional
temperature/moisture content-controlled schedulesa |
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Condition |
4/4,
5/4 |
6/4
stock |
8/4 |
10/4 |
12/4 |
British
schedule |
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Standard |
T8-B3 |
NA |
T5-B2 |
NA |
NA |
G |
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aReference
(74, 185). |
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Working
Properties:
Pacific yew wood works well with tools. It splits during nailing but hold
screws well. It bends easily, is excellent for turnery and finishes smoothly.
Durability: Pacific yew is rated as
exceptionally high in resistance to heartwood decay (10). It may be used for
outdoor purposes without preservative treatment.
Preservation: No information
available at this time.
Uses: Archery bows, turnery,
cabinetry, canoe paddles, veneer, marquetry, panelling, carvings, furniture,
joinery, fences, door, tables, rustic furniture.
Toxicity: May cause irritation
and /or dermatitis (3,7&11). The word toxic is based on Taxus.
Additional
Reading and References Cited (in parentheses)
1. Bolsinger, C.
L. and Jaramillo, A. E. Taxus brevifolia Nutt. Pacific Yew. in: Burns, R. M. and
Honkala, B. H., tech. coords. Silvics of North America. Volume 1, Conifers.
Washington, DC: USDA Forest Service; 1990; pp. 573-579.
2. Boone, R. S.;
Kozlik, C. J.; Bois, P. J., and Wengert, E. M. Dry kiln schedules for
commercial woods - temperate and tropical. Madison, WI: USDA Forest Service,
FPL-GTR-57; 1988.
3. Hausen, B. M.
Woods injurious to human health. A manual. New York, NY: Walter de Gruyter;
1981.
4. Henderson, F.
Y. A handbook of softwoods. London: HMSO; 1977.
5. Hyam, R. and
Pankhurst, R. Plant and their names. A concise dictionary. Oxford, UK: Oxford
University Press; 1995.
6. Markwardt, L.
J. and Wilson, T. R. C. Strength and related properties of woods grown in the
United States. Washington, DC: USGPO, USDA Forest Service, Tech. Bull. No. 479;
1935.
7. Mitchell, J.
and Rook, A. Botanical dermatology: plants and plant products injurious to the
skin. Vancouver, BC: Greenglass Ltd.; 1979.
8. Simpson, W.
T. Dry kiln operator's manual. Madison, WI: USDA Forest Service, FPL Ag.
Handbook No. 188; 1991.
9. Summitt, R.
and Sliker, A. CRC handbook of materials science. Vol. 4. Boca Raton, FL: CRC
Press, Inc.; 1980.
10. USDA. Wood
handbook: wood as an engineering material. Madison, WI: USDA Forest Service,
FPL Ag. Handbook No. 72; 1974.
11. Woods, B.
and Calnan, C. D. Toxic woods. British Journal of Dermatology. 1976;
95(13):1-97.