View source for Taxus brevifolia

{{Inc|
Taxus brevifolia, Nutt. Fig. 3782 (adapted from Pacific R. R. Report). Tree, 40-50 or occasionally 80 ft. high, with slender horizontal or somewhat pendulous branches forming a broad, open, pyramidal head: lvs. distinctly 2-ranked, sharply pointed, dark yellowish green, 1/2 – 3/4 in. long: seeds ovoid, 2-4-angled. Brit. Col. to Calif. S.S. 10:514.—Probably as hardy as T. baccata.
}}

{{Taxobox
| color = lightgreen
| name = ''Taxus brevifolia''
| status = LR/nt
| image = PacificYew_7591.jpg
| image_width = 240px
| image_caption = ''Taxus brevifolia'' (Pacific Yew) foliage
| regnum = [[Plant]]ae
| divisio = [[Pinophyta]]
| classis = [[Pinophyta|Pinopsida]]
| ordo = [[Pinales]]
| familia = [[Taxaceae]]
| genus = ''[[Taxus]]''
| species = '''''T. brevifolia'''''
| binomial = ''Taxus brevifolia''
| binomial_authority = [[Thomas Nuttall|Nutt.]]
}}
[[Image: PacificYew_7684.jpg|thumb|Pacific Yew foliage underside]]
[[Image: PacificYew_8544.jpg|thumb|Pacific Yew form]]
'''''Taxus brevifolia''''' ('''Pacific Yew''' or '''Western Yew''') is a [[Pinophyta|conifer]] native to the [[Pacific Northwest]] of [[North America]]. It ranges from southernmost [[Alaska]] south to central [[California]], mostly in the [[Pacific Coast Ranges]], but with an isolated disjunct population in southeast [[British Columbia]] and south to central [[Idaho]].

It is a small to medium-sized [[evergreen]] [[tree]], growing 10-15 m tall and with a trunk up to 50 cm diameter, rarely more.

It has thin scaly brown [[bark]]. The [[leaf|leaves]] are lanceolate, flat, dark green, 1-3 cm long and 2-3 mm broad, arranged spirally on the stem, but with the leaf bases twisted to align the leaves in two flat rows either side of the stem except on erect leading shoots where the spiral arrangement is more obvious.

The [[conifer cone|seed cones]] are highly modified, each cone containing a single [[seed]] 4-7 mm long partly surrounded by a modified scale which develops into a soft, bright red [[berry]]-like structure called an [[aril]], 8-15 mm long and wide and open at the end. The arils are mature 6-9 months after pollination, and with the seed contained are eaten by [[Thrush (bird)|thrushes]] and other [[bird]]s, which disperse the hard seeds undamaged in their droppings; maturation of the arils is spread over 2-3 months, increasing the chances of successful seed dispersal. The male cones are globose, 3-6 mm diameter, and shed their [[pollen]] in early spring. It is mostly [[Plant sexuality|dioecious]], but occasional individuals can be variably [[Plant sexuality|monoecious]], or change sex with time.

===Uses===
The [[chemotherapy]] drug [[paclitaxel]], used in [[breast cancer|breast]], [[ovarian cancer|ovarian]] and [[lung cancer]] treatment, is derived from ''Taxus brevifolia''. Over-harvesting for production of this drug has resulted in the Pacific Yew becoming a rare species, despite the fact the drug can be produced semi-synthetically from cultivated yews. Pharmaceutical use of closely-related wild yew species in India and China threatens some of those species as well.{{fact|date=July 2007}}

<gallery>
Image: PacificYew_8538.jpg|Pacific Yew foliage
Image:PacificYew_7790.jpg|Pacific Yew mat form
Image: PacificYew_8566.jpg|Pacific Yew bark 
</gallery>

==References==
* {{IUCN2006|assessors=Conifer Specialist Group|year=1998|id=34041|title=Taxus brevifolia|downloaded=05 May 2006}}
* Heiken, D. (1992). The Pacific Yew and Taxol: Federal management of an emerging resource. ''Journal of Environmental Law and Litigation'' 7: 175.
*[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501253 Flora of North America: ''Taxus brevifolia''] [http://www.efloras.org/object_page.aspx?object_id=7082&flora_id=1 RangeMap:]
* [http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_1/taxus/brevifolia.htm US Forest Service Silvics Manual: ''Taxus brevifolia'']
* [http://www.fs.fed.us/global/iitf/pdf/shrubs/Taxus%20brevifolia.pdf US Forest Service: ''Taxus brevifolia''] (pdf file)
* [http://www.botgard.ucla.edu/html/botanytextbooks/economicbotany/Taxus/index.html UCLA text on "Economic Botany"]

[[Category:Taxaceae]]
[[Category:Trees of Northwestern United States]]
[[Category:Trees of Alberta]]
[[Category:Trees of British Columbia]]
[[Category:Trees of Washington]]
[[Category:Trees of California]]
[[Category:Trees of Idaho]]
[[Category:Trees of Montana]]
[[Category:Trees of Oregon]]
[[Category:Medicinal plants]]