Taxus baccata (common yew) | Plants & Fungi At Kew Discover plants and fungi Taxus baccata (common yew) A densely branching evergreen that can live for centuries, the common yew is often found in British churchyards. Taxus baccata on a ruined wall at Waverley Abbey, Surrey. Species information Least Concern (LC) according to IUCN Red List criteria. Habitat: Oak and beech woodland, often on chalk or limestone substrates. Key Uses: Ornamental, timber, wood for bow-making, medicinal. Known hazards: The seeds, leaves and bark are highly poisonous and can cause fatal poisoning of humans and livestock. Taxonomy Genus: Taxus About this species Taxus baccata, although native to Britain and sometimes referred to as the English yew, is also found across much of Europe, western Asia and North Africa. The generic name Taxus is reflected in the name of the poisonous taxanes found in the tree. Some botanists did not consider yew to be a true conifer, since it does not bear its seeds in a cone.

However, proper consideration of its evolutionary relationships now places the yew family (Taxaceae) firmly within the conifers. Medicinal Uses Yew trees contain the highly poisonous taxane alkaloids that have been developed as anti-cancer drugs. Eating just a few leaves can make a small child severely ill and fatalities have occurred. All parts of the tree are poisonous, with the exception of the bright red arils. The arils are harmless, fleshy, cup-like structures, partially enveloping the seeds, which are eaten by birds (which disperse the seeds); however, the black seeds inside them should not be eaten as they contain poisonous alkaloids. Discover more Geography and distribution The common yew is found across much of Europe, western Asia and North Africa. It grows throughout the British Isles (although it is less abundant in Ireland, and absent from the far north of Scotland), especially on calcareous soils. Ancient yew woods, formed of almost pure stands of yew, are a typical feature of chalk soils in southern England (for example along the North Downs and in the Chiltern Hills). Taxus baccata ripe seeds enclosed by a bright red aril.

Description Taxus baccata is a densely branching, evergreen tree with a massive trunk, reaching up to 20 m tall. The leaves are dark green, linear and up to 3 cm long, with a pointed tip, and appear to spread in two rows on either side of the shoot. Unlike many other conifers, the common yew does not actually bear its seeds in a cone. Instead, each seed grows alone at the tip of a dwarf shoot, enclosed in a fleshy, usually red, aril which is open at the tip and up to 1 cm in length. How old is a yew tree? Taxus baccata in Kentchurch Court deer park, Herefordshire While it is generally agreed that the yew lives for a long time, the actual age of individual trees is often impossible to judge. The traditional method of counting the rings in the trunk of a tree is often not an option, because many older specimens develop hollow trunks. This is caused by a fungus that turns the inside of the tree into a pulpy, soil-like mass of rotten wood (which seems to have no ill-effect on the health of the tree as a whole).

However, as yew trunks have been known to reach huge girths of as much as 4 m (13 ft), even the most conservative estimates of around 2,000 years of age, place them as the longest-living trees in Europe. Taxus baccata foliage and pollen cones In 2000, Kew scientists in the Jodrell Laboratory at Kew used their skills in plant anatomy and chemistry to solve the death of two horses. Tim Lawrence was able to detect fragments of yew leaves in the stomach contents of the horses while Dr Geoffrey Kite developed a method to detect the toxic yew-derived taxane alkaloids in the stomach contents using liquid chromatography-mass spectrometry (an analytical chemistry technique using physical separation and mass analysis). Dr Kite has since used his liquid chromatography-mass spectrometry method to investigate other horse deaths, suspected as being caused by yew. Millennium Seed Bank: Seed storage Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Description of seeds: Average 1,000 seed weight = 60.3 g. Seeds are dispersed by birds. Number of seed collections stored in the Millennium Seed Bank: One. Seed storage behaviour: Orthodox (the seeds of this plant survive drying without significant reduction in their viability, and are therefore amenable to long-term frozen storage such as at the MSB) Germination testing: 84% germination achieved with pre-sowing treatments (imbibed on 1% agar for 20 weeks at 5°C, then imbibed on 1% agar for 20 weeks at 20°C, then 1% agar at 5°C for 21 weeks) and then on a germination medium of 1% agar, at a temperature of 20°C, on a cycle of 8 hours light/16 hours darkness. This species at Kew The parterre in front of Kew Palace is surrounded on all sides by a hedge of common yew. Yew trees can also be seen in the woodland of the Conservation Area close to Queen Charlotte’s Cottage. There are some spectacular examples of yew trees growing with their roots climbing down over sandstone rocks at Wakehurst.

Kew at the RHS Chelsea Flower Show 2011 In 2011, Kew partnered with The Times to produce a show garden to showcase the significance of plants to science and society. The garden, designed by Chelsea gold medallist Marcus Barnett, featured species chosen to demonstrate both beauty and utility, including medicinal, commercial, and industrial uses to underline the fact that plants are invaluable to our everyday lives – without them, none of us could live on this planet; they produce our food, clothing and the air that we breathe. Taxus baccata was one of the species that featured in the garden, which was awarded a Silver Medal. References and credits Bevan-Jones, R. (2007). The ancient yew, a history of Taxus baccata. Windgather Press, Bollington, Cheshire. Conifer Specialist Group (1998). Taxus baccata. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. < . Downloaded on 02 November 2010. Cooper, M.R. & Johnson, A.W. (1998).

Poisonous Plants and Fungi in Britain: Animal and Human Poisoning. The Stationery Office, London. Farjon, A. (2010). A Handbook of the World’s Conifers. E.J. Brill, Leiden & Boston. Huxley, A., Griffiths, M. & Levy, M. (eds) (1992). The New Royal Horticultural Society Dictionary of Gardening. Vol. 4 (R to Z): 437-438. Macmillan Press, London. Kite G.C., Lawrence T.J. & Dauncey E.A. (2000) Detecting Taxus poisoning in horses using liquid chromatography/mass spectrometry. Vet. Hum. Toxicol. 42(3):151-154. Preston, C.D., Pearman, D.A. & Dines, T.A. (eds) (2002). New Atlas of the British and Irish Flora: An atlas of the Vascular Plants of Britain, Ireland, the Isle of Man and the Channel Islands. Oxford University Press, Oxford. Wageneder, F. (2007).

Yew, a history. Sutton Publishing Ltd., Stroud. Kew Science Editor: Aljos Farjon Kew contributors: Sustainable Uses Group Copyediting: Emma Tredwell While every effort has been taken to ensure that the information contained in these pages is reliable and complete, the notes on hazards, edibility and suchlike included here are recorded information and do not constitute recommendations. No responsibility will be taken for readers’ own actions. Taxus (yew) description T. sumatrana The species of Taxus are more geographically than morphologically separable; they were all treated by Pilger (1903) as subspecies of T. baccata. All species are poisonous; most contain the anti-cancer agent taxol; and a study of heartwood constituents of T. baccata, T. brevifolia, T. cuspidata and T. floridana found them to be chemically almost identical ( Hartzell 1991 ). However, the vast ecological amplitude displayed by the various described species (over 60° of latitude and an impressive temperature and precipitation range) suggests that they are, in a meaningful sense, true species.

"Detailed study of the genus (not neglecting the cultivated representatives), including extensive fieldwork, is much needed and long overdue" ( Hils 1993 ). There are hundreds of yew cultivars ( Hartzell 1991 ). Description "Trees or shrubs, dioecious or monoecious. Bark reddish brown, scaly. Branches ascending to drooping; twigs irregularly alternate, green or yellow-green when young, reddish brown in age. Leaves often appearing 2-ranked, flexible; stomates abaxial, in 2 broad, pale bands; apex soft-pointed, mucronate, not sharp to touch; resin canal absent. Pollen cones globose, yellowish, with 4 - 16 peltate sporophylls, each bearing 2 - 9 sporangia. Ovule 1. Seed maturing in 1 season, brown; aril scarlet to orange-scarlet, soft, mucilaginous, thick, cup-shaped, open at apex, exposing hard seed coat; albumen uniform. x = 12" ( Hils 1993 ). Distribution and Ecology Europe: Britain to N Iran.

Asia: Russia, Korea, Japan, China, Taiwan, Himal, India, Burma, Vietnam, Philippines. N America: SE Alaska to California, SE Canada to NE USA, Florida, Mexico, Guatemala, El Salvador ( Silba 1986 ). The eight species are almost wholly allopatric and largely confined to the middle latitudes of the northern hemisphere, with some intrusion to tropical highlands, the northernmost occurrence being in Norway and the southernmost below the equator in the S Celebes. Plants are found in the understory or canopy of moist temperate or tropical mountain forests. Their elevation ranges from near sea level in northern stations to 3000 m in tropical forests ( de Laubenfels 1988 ). Big tree TOXIKON (poison); a yew extract was used as an arrow poison ( Hartzell 1991 ). Paleobotany: The oldest recognizable yew is the Triassic Paleotaxus rediviva, found in strata 200 ma old. The mid-Jurassic Taxus jurassica (140 ma old) is more recognizable as a member of Taxus, containing features characteristic of T. baccata, T.

cuspidata, and T. brevifolia. A Quaternary yew, Taxus grandis, is probably simply T. baccata ( Hartzell 1991 ). "The foliage, bark, and seeds - but not the fleshy red aril - of most Taxus species are toxic due to the presence of taxine (Kingsbury 1964, Cooper et al. 1984); this alkaloid, however, was not found in T. brevifolia (Jones and Lynn 1933). Two Eurasian species,T. baccata (English yew) and T. cuspidata (Japanese yew), are best known and documented for toxicity. Cattle have been poisoned by T. canadensis planted in British Columbia, but toxicity of T. brevifolia has not been conclusively recorded (Kingsbury 1964). Although horses, cattle, and humans have been poisoned by ingesting yew leaves and seeds, the fresh foliage of T. canadensis is browsed by deer, and that of T. brevifolia by moose" ( Hils 1993 ).

Pollination is by wind dispersal. Seed dispersal is primarily by birds, which eat the seeds in the aril and subsequently excrete viable seed ( de Laubenfels 1988 ). Citations Cooper, M.R. and A.W. Johnson. 1984. Poisonous plants in Britain and their effects on animals and man. London. [Minist. Agric., Fisheries & Food Ref. Book 161.] Jones, I. and E. V. Lynn. 1933. Differences in species of Taxus. Journal of the American Pharmaceutical Association 22:528-531. Kingsbury, J. M. 1964. Poisonous plants of the United States and Canada. Englewood Cliffs. See also Chadwick, L.C. and R.A. Keen. 1976. A study of the genus Taxus. Ohio Agricultural Experiment Station Bulletin 1086. Keen, R. A. and L. C. Chadwick. 1955. Sex reversal in Taxus. American Nurseryman 100(6):13-14. Keen, R.

A. 1956. A study of the genus Taxus. Ph.D. thesis. Ohio State University. Li, J., C.C. Davis, P. Del Tredici and M.J. Donoghue. 2001. Phylogeny and biogeography of Taxus (Taxaceae) inferred from sequences of the internal transcribed spacer region of nuclear ribosomal DNA. Harvard Papers in Botany 6: 267-274. Taxus baccata, yew - THE POISON GARDEN website THE POISON GARDEN website Taxus baccata, yew Summary Rich in myths, legends and folklore. The berries are a good example of why advising a child to always chew its food thoroughly is not universally sound. Blog Entries Meaning of the Name Taxus Possibly from the Greek ‘taxon’, ‘bow’ as a result of the use of its wood to make bows. Persian has ‘tachš’ for ‘bow’.

A mummy from the Chalcolithic age, around 4000BC, was found with an unfinished bow made of yew so its use for this purpose goes back much further than the English long bowmen usually associated with it. yew, Irish yew, English yew How Poisonous, How Harmful? Taxus baccata, yew All parts, except the flesh of the berries, contain taxin(e) a complex of alkaloids which is rapidly absorbed. Also present are ephedrine, a cyanogenic glycoside (taxiphyllin) and a volatile oil. Where poisoning does occur, in animals or humans, there may be no symptoms and death may follow within a few hours of ingestion. If symptoms do occur, they include trembling, staggering, coldness, weak pulse and collapse. Yew is one of the plants where the poison is not destroyed when the plant dies. Thus, branches removed from a yew by high winds or pruning will retain their poison. Though the berries are harmless, the seed within is highly toxic. Unbroken it will pass through the body without being digested but if the seed is chewed poisoning can occur with as few as three berries.

Taxus baccata, yew Incidents Most incidents with yew relate to animals though it was eaten, in the 1980s, by four prisoners as a means of suicide. Three of the four succeeded. The interactive CD-ROM produced by St Thomas' and Kew Gardens cites a number of case reports all involving ingestion of leaves or bark. In one case it is noted that a nineteen month old child accidentally ingested some plant material. Intact seeds were found in his stools confirming that these are not digested. The child recovered. Farmers have reported cases of poisoning in cattle when dead yew clippings have been dumped on grazing land. The assumption is that someone clipped a yew hedge in the garden, left the clippings to wither thinking that would render them safe before 'recycling' them by dumping them on farmland. A visitor to the Alnwick Garden Poison Garden talked about his elderly neighbour who, being no longer able to manage it himself, had a group of young people in to tidy up his garden. They trimmed his yews and threw the clippings over the fence into the field at the bottom of the garden where three heifers died after eating the cuttings.

Folklore and Facts Some years ago, it was found that the taxol found in yew could be used to produce chemotherapy treatments for breast and other cancers. The drug produced in this way is called paclitaxel. (Until someone was kind enough to correct me, I was one of the many people who thought tamoxifen was produced from yew. It is not. Tamoxifen is a synthetic drug.) For some time, large gardens made a point of keeping their yew prunings and passing these to companies to extract the taxol and produce these drugs. This was an expensive process and produced only limited amounts of the drug. Since then, however, it has been discovered that taxol is produced from a fungus that lives in the yew. Other fungi have also been found that are able to be used to produce paclitaxel. With some, artificially brewing is possible and, once that process is scaled up, it should reduce the cost and increase the availability of breast cancer treatments. Though toxic to most animals, deer do graze on yew and gardeners are advised to avoid growing yew if there is a possibility of deer getting into the garden because it is a favourite food.

That said, the list of plants which deer will browse is a very long one and there are reports of poisoning incidents so it may be large amounts are toxic to deer. The idea that yew was grown in churchyards for making longbows is a myth. Bows were made, primarily, from the trunk of the tree so the tree was destroyed. In addition, yew grown in Britain is too brittle so the famous English longbow was made from wood imported from Europe. The roots of the yew are very fine and will grow through the eyes of the dead to prevent them seeing their way back to the world of the living. Sources - Galen Galen was a Greek who worked as a doctor in Rome. He lived from about 130AD to about 215AD. He spent much time dissecting animals to try and understand the workings of the body and was the first to conclude that the kidneys are where urine is formed rather than the bladder. He also discovered the heart valves and found that the arteries carry blood around the body and not air as was thought. Many of his other discoveries were, however, erroneous and he fell out of favour during the Renaissance.

That we know so much of Galen’s writings is due to their translation into Arabic, during the 9th century, by Hunayn ibn Ishaq. Many of the English herbals refer to Galen to support their descriptions of the efficacy of plant remedies. Yew is very long-lived and, in many cases, the yew tree in the churchyard predates the church so, the church was built round a yew tree because the pagan belief about the roots was so deep-seated. Its longevity leads to its featuring in tales of reincarnation. If two yews are intertwined it is believed that they grew after yew stakes were driven into the chests of lovers whose relationship appalled their community. Many place names have their origins in particular trees. York is a corruption of an Anglo-Saxon word meaning ‘the place where yew grows’. John Gerard quotes Galen and others as saying that the yew is very venomous taken internally and that sleeping under a Yew can cause sickness and oftentimes death.

He then dismisses these stories by saying that ‘when I was young and went to school, divers of my school fellows and likewise myself did eat our fills of the berries of this tree and hath not only slept under the shadow thereof, but among the branches also, without hurt at all, and that not one time, but many times’. Thomas Johnson resolves the difference of opinion between the foreign ancient sources and Gerard by asserting that the yew in England is not poisonous but, in other countries, it is highly venomous. Site Update All the pages in the A to Z section are regularly updated. Irish Yew - Taxus baccata âFastigiataâ - PNW Plants Fruit Description Most commonly used for hedging purposes, Irish Yew has a naturally upright form and takes shearing well. It's an option for gardeners looking for an alternative to more common Eastern Arborvitae (Thuja occidentalis). Morphology: Taxus baccata âFastigiataâ will reach 7â â 8â high by 3â wide in ten years. Ultimately, it can reach up to 20 feet high if left un-pruned.

It naturally makes a good shape without any clipping or trimming. It holds its branches in an upright rigid fashion. Needles are linear in shape with an acute tip. This is a female cultivar that produces red berries in the fall. Children should be kept away from the berries as they find them attractive. Unfortunately they are poisonous. Adaptation: Taxus baccata âFastigiataâ prefers well-drained acidic soil and is drought tolerant once established. Plant it in full sun or shade. All parts of the yew plant (bark, and foliage included) can be toxic, so site plants with care. Pests: Plants Profile for Taxus (yew) Taxus L. – yew Subordinate Taxa The Plants Database includes the following 6 species of Taxus. Click below on a thumbnail map or name for species profiles. Taxus cuspidata (Japanese Yew) Home » Taxus cuspidata (Japanese Yew) Taxus cuspidata Taxus baccata L. ssp. cuspidata (Siebold & Zucc.) Pilg. Taxus baccata L. var. microcarpa Trautv. Taxus cuspidata Siebold & Zucc. var.

latifolia (Pilg.) Nakai Taxus cuspidata Siebold & Zucc. var. microcarpa (Trautv.) S.Y.Hu Taxonomic Source(s): Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden. Taxonomic Notes: Two varieties are recognized: the nominate variety (var. cuspidata) occurs throughout the range of the species and var. nana which is only known from Japan and the Russian Far East. The occurrence of this latter variety is poorly documented; both its taxonomic status and its occurrence are in need of further investigation. Thomas, P. & Farjon, A. Justification: Exploitation of this species has only affected subpopulations in certain parts of its extensive range, hence it is assumed that population reduction has been limited and has not had sufficient impact to warrant any assessment other than Least Concern.

Previously published Red List assessments: 1998 – Lower Risk/least concern (LR/lc) Geographic Range [top] Range Description: Recorded from the Russian Far East: Kuril Is., Sakhalin, Primorye; China: Heilongjiang, Jilin, Liaoning, Shaanxi; North Korea; South Korea; and Japan. The extent of occurrence is in excess of 20,000 km2. The area of occupancy has not been estimated. Countries occurrence: Native: China (Heilongjiang, Jilin, Liaoning, Shaanxi); Japan (Hokkaido, Honshu, Kyushu, Shikoku); Korea, Democratic People's Republic of; Korea, Republic of; Russian Federation (Kuril Is., Primoryi, Sakhalin) Additional data: Population [top] Population: The overall population trend is likely to be stable although there may have been some decline in areas where clear-felling of forests has occurred..

Current Population Trend: Habitat and Ecology [top] Habitat and Ecology: Taxus cuspidata occurs sparsely in mixed conifer and conifer-deciduous broad-leaved forests in lowland to lower montane altitudes from 100 m to 1,600 m a.s.l. In NE China it occurs in conifer forest with Abies nephrolepis, Picea jezoensis, Pinus koraiensis, and Larix gmelinii var. olgensis, in Sakhalin Island and northern Japan with Abies sachalinensis, Picea glehnii, P. jezoensis, Larix kaempferi, and various angiosperm trees e.g. Acer spp., Betula spp., Populus maximowiczii, Juglans mandshurica, Sorbus aucuparia, Ulmus spp., and Kalopanax ricinifolium. Further south in Japan it is common in the understorey of woods with Acer spp., Ulmus davidiana var. japonica, Tilia japonica, Juglans ailanthifolia, Quercus mongolica var. grossesserata, and many other species of trees.

It grows on a variety of soils derived from granitic, schistose or serpentine base rocks. The variety nana is mostly found growing on rocky sea coasts but may also occur on exposed rock outcrops in the interior. Systems: Use and Trade [top] Use and Trade: The wood of this yew is used in China for construction, cooperage, for the making of furniture and for wood carving and turning. In Japan it is prized for interior finish, household furniture, utensils, marquetry, wood turning and sculpture; on a more industrial scale it is used to make pencils. The Ainu people of Hokkaido and Sakhalin made their bows, as well as the scabbards of hunting knives, from its wood. The heartwood yields a brown or red dye. Extracts of many parts of the plant (roots, wood, bark and leaves) are used in traditional Chinese medicine (treating diabetes) while in modern times the pharmaceutical industry became much interested in the anti-cancer properties of its alkaloids (taxanes, drug name: Taxol®), which appear to be present in all species in low but varying concentrations.

The seeds contain oils which are also extracted, but treatment is required to neutralize the poisonous alkaloids. In horticulture it has been so popular for a long time that the species is now rare in the wild, but it is grown nearly everywhere in the urbanized areas of Japan. Numerous cultivars exist, and the species is used in bonsai culture. Japanese yew was introduced to Europe (England) in 1855 by Robert Fortune and more cultivars have been developed here as well as in the USA. A hybrid between T. baccata and T. cuspidata (Taxus ×media Rehd.) originated in the USA around 1900 and has given rise to further cultivars. Threats [top] Major Threat(s): This species has been listed on CITES Appendix II in connection with the exploitation of its foliage for the extraction of chemicals active as an anti-cancer drug. This exploitation was localized and has not resulted in significant decline throughout the wide range of this species. Conservation Actions [top] Conservation Actions: This species has been listed on CITES Appendix II and is also recorded from various protected areas in most parts of its range. Citation: Katsuki, T.

& Luscombe, D. 2013. Taxus cuspidata. The IUCN Red List of Threatened Species 2013: e.T42549A2987373. . Downloaded on 19 January 2017. Disclaimer: Taxus Baccata (Common Yew / English Yew) Taxus Baccata (Common Yew / English Yew) Taxus baccata is a medium sized, evergreen conifer, native to Britain, much of Europe and parts of Asia and Africa. It is tolerant of a wide range of growing conditions including shade and chalk but not waterlogged or poor draining soil. It is widely used in landscaping as its relatively slow growth and tolerance of pruning make it an ideal plant for hedging and topiary. Bright red, berry like fruits ripen in the autumn and are attractive to birds during the winter. Most parts of the plant are toxic, particularly if foliage is eaten by animals. Fatal poisoning is uncommon in humans though unless excess volumes of foliage are consumed! Taxus baccata is the longest living plant in Europe with estimated ages between 2000 and 4000 years.

However, no one can determine the exact ages as the trunk hollows with age, making a ring count impossible. This does not make the plant unstable though as once it reaches a certain size, new shoots appear at the base and grow, fusing into the main truck and acting like buttresses. Common Name: Common, English or European Yew Family: Taxaceae Demands: Tolerant of most conditions and soil types as long as well drained Foliage: Needles are lanceolate, flat and dark green Bark: Reddish-brown, flaking in small pieces Fruit: Seeds are surrounded by a red, berry-like fruit. Taxus baccata info sheet FACT: Most commonly, people associate Yews with churchyards. Ancient Britons planted them near temples and when Christianity came to Britain, the tradition continued. Some churches were built by existing plants. Around 500 churchyards in England have a yew tree which is older than the church itself, they are meant to be a symbol of everlasting life and resurrection. Yew has a long history in England as the wood of choice for bow making. The heartwood is on the inside of the bow as it resists compression.

The sapwood is on the outside as it resists stretching. Once all the British supplies had been exhausted, the wood was imported from Europe. Once the European supplies were exhausted, longbows were replace with firearms! Taxus baccata clipped cones Taxus brevifolia Nutt Taxus brevifolia Nutt. Taxaceae -- Yew family Charles L. Bolsinger and Annabelle E. Jaramillo Pacific yew (Taxus brevifolia), also called western yew, is a coniferous tree associated with several conifer and hardwood tree species on a variety of sites. Pacific yew tolerates shade, and in undisturbed stands is usually found as an understory tree. Growth of such trees is slow, but where the overstory has been removed or thinned, diameter growth on undamaged yew trees may increase considerably. Pacific yew rarely exceeds 60 cm (24 in) in d.b.h., and 15 m (49 ft) in height. The largest on record is 142 cm (56 in) in d.b.h., and 18 m (60 ft) in height (28).

The wood is hard, heavy, and resistant to decay. Although not of great interest to the forest products industry, it has many special uses. The bark of Pacific yew contains a drug, taxol, that is being used in cancer research, so demand for yew bark by the National Cancer Institute has increased dramatically in recent years (9). Habitat Native Range Pacific yew grows in forests from the southern tip of southeast Alaska- including Annette and Prince of Wales Island- south through the Pacific Coast region of British Columbia, Vancouver and the Queen Charlotte Islands, and the Olympic Peninsula of Washington. It is rare in the Coast Range south of the Olympic Peninsula in Washington and north of the Umpqua River in Oregon, but occurs with greater frequency in the Coast Range in southern Oregon and northern California. Isolated occurrences are found as far south as Marin and San Mateo Counties in California. Yew occurs in scattered localities in the valleys between the Coast Range and Cascade Ranges of Oregon and Washington. In the Cascade Range, it is fairly common at low to moderate elevations, and on some sites in southern Oregon it is abundant.

Pacific yew extends south through the Klamath Mountains of California, then southeasterly to the western slopes of the Sierra Nevada. Its southern limit is in Calaveras County. Farther inland, it grows on the western slopes of the Rocky Mountains in British Columbia, south into northern Idaho and western Montana, the Lewis Range in Montana, and isolated areas in eastern Washington and northeastern Oregon. In the South Fork of the Clearwater River basin in Idaho, Pacific yew deviates from its role as a minor forest component and becomes a dominant on about 16 000 hectares (40,000 acres) (8,19,20,27,30,31,35,40,42,43, 44,47,49). - The native range of Pacific yew. Climate Pacific yew is found over a wide range of moisture and temperature conditions (8,11,19,35,40,44). In dry, subhumid areas with an average annual precipitation as low as 470 mm (19 in), it is confined to streamside areas and the lower third of north-facing slopes.

Some large specimens can be found in such environments; for example, the largest known yew tree in Idaho- 84.8 cm (33.4 in) d.b.h. and 8.5 m (28 ft) tall- is at the bottom of Hell's Canyon in an area that receives about 500 mm (20 in) of precipitation annually (21). On the Queen Charlotte Islands, Pacific yew is confined to the borders of inlets (44). Throughout much of its range within humid and superhumid forests (precipitation of 1400 to 4000 mm [55 to 157 in]), it can be found on all slopes, benches, and ridgetops. For example, a large yew tree in Oxbow County Park near Troutdale, Oregon (precipitation about 1450 mm [57 in]), is on the highest point in the park, a 210-m (690-ft) ridge overlooking the Sandy River 168 m (550 ft) below (3).

Pacific yew is found from sea level in coastal areas to 2440 m (8,000 ft) in the Sierra Nevada. Length of growing season ranges from 60 to 300 days, with annual minimum temperatures from -15° to -12° C (5° to 10° F) (4,8,11,24,25,35,45). Soils and Topography Pacific yew grows best on deep, moist or rich, rocky or gravelly soils. In dry interior forests, the species develops best along mountain streams, and in shady canyons, ravines, and coves. Within the moist maritime climate of the Pacific Northwest, it grows most abundantly in drier, warmer environments. A partial list of soils on which Pacific yew grows includes those in the orders Ultisols, Alfisols, and Inceptisols (4,11,20,24,25,27,30,37,45,50). Associated Forest Cover Pacific yew commonly occurs as an understory species in several forest cover types.

It is a major component in some stands, but in most it is minor to rare. In some types, it tends to be found mostly on microsites. Some examples: In stands of ponderosa pine (Pinus ponderosa), grand fir (Abies grandis), and western larch (Larix occidentalis) in the drier interior forests, yew is found in moist areas near streams and springs (but on well drained soil); on wet, hummocky sites west of the Cascades, yew can be found in Oregon white oak (Quercus garryana)-Oregon ash (Fraxinus latifolia) stands (ash occupies the low, wet spots and yew grows with the oak on slightly raised hummocks); scattered large yew trees grow along the Clackamas River in northwest Oregon on berms and banks between first and second bottomlands in stands of black cottonwood (Populus trichocarpa), red alder (Alnus rubra), hawthorn (Crataegus spp.), crab apple (Malus spp.), and willow (Salix spp.) (3,47). By far, Pacific yew is most common in dense conifer forests.

Among the major Society of American Foresters (16) cover types in which Pacific yew is found are: Engelmann Spruce-Subalpine Fir (206), Interior Douglas-Fir (210), White Fir (211), Grand Fir (213), Black Cottonwood-Willow (222), Western Hemlock (224), Western Redcedar-Western Hemlock (227), Western Redcedar (228), Pacific Douglas-Fir (229), Douglas-Fir-Western Hemlock (230), Port-Orford-Cedar (231), Redwood (232), Oregon White Oak (233), Douglas-Fir-Tanoak-Pacific Madrone (234), Sierra Nevada Mixed Conifer (243), and Pacific Ponderosa Pine-Douglas-Fir (244) (4,8,11,17,24,25,35,45,47). In western Oregon, Douglas-fir was present on 89 percent of the forest inventory plots in which yew was tallied.

A list of plants found most frequently with Pacific yew on these plots (table 1) indicates the broad range of conditions to which the species can adapt. Table 1- Plants frequently found on plots with Pacific yew present, western Oregon. Species ¹Based on information from 4,24, and 45. Life History Reproduction and Early Growth Flowering and Fruiting- Pacific yew is dioecious. Male strobili are stalked, bud-like, pale yellow, and composed of 6 to 12 filamentous stamens, each with 5 to 9 anthers. They are abundant on the underside of branch sprays and usually appear in May or June. Female strobili are less abundant, greenish, and composed of several scales. They also are borne on the underside of branches. The fruit is an ovoid-oblong seed about 8 mm (0.3 in) long, partially enveloped by a fleshy, berrylike, scarlet, cup-shaped disk called an aril. Pollen is dispersed by wind in the spring (6,11,19,22).

Seed Production and Dissemination- Fruits ripen from August to October of the same year that flowering occurs. Fruits either drop to the ground or are taken from trees by birds or rodents. Birds devour the fleshy arils and void the seeds which remain viable. Chipmunks and squirrels often take only the seeds. Rodents and some birds-nuthatches, for example-cache yew seeds, thus creating the clusters of yew seedlings observed in some areas (11). The seed is about 6 mm (0.24 in) long with a depressed hilum, bony inner coat, and membranous outer seedcoat. Pacific yew is a prolific seeder (19,43). Seeds average about 33,100/kg (15,000/1b) after cleaning (39). The frequency of good seed crops is unknown. Seedling Development- Seeds of Pacific yew germinate slowly and require stratification. Germination tests indicate that 30° C (86° F) day and 20° C (68° F) night temperatures are desirable (11,19,43).

Germination is epigeal, and usually in heavy organic matter. In a study in Idaho, wild yew seedlings were distributed in seedbeds as follows (1l): Type of seedbed _3_ 100 Yew seeds sown in nursery beds in late spring require mulching. Beds require shading during the summer and again in December. Some seeds do not germinate until the second spring after sowing (39). Vegetative Reproduction- Pacific yew is capable of layering and often sprouts from stumps or rootstocks after the top has been killed or the tree cut (3,11,23,44). Layering usually occurs after branches or tree tops have been pressed to the ground for a prolonged period by large fallen trees or limbs (11), although occasional old yew trees can be found surrounded by a ring of well rooted branches that were apparently held down only by their own weight and the weight of snow in the winter. Although Pacific yew is sensitive to heat (11,26,44), sprouts that originated from the bases of burned stumps were reported from the Rogue River National Forest in southern Oregon (23).

Young yew trees that originated by layering and sprouting were observed in a sunny, south-facing clearcut on the Mount Hood National Forest in northern Oregon. From one cut yew tree with a stump diameter of 30 cm (12 in), seven new trees had originated by layering before cutting, and a clump of vigorous stump sprouts had originated after cutting. Sprouts emerged from one side of the 36-cm-high (14 in) stump (the opposite side had been debarked during logging) from ground level to the top. The layers were 1.0 m to 2.5 m (3 ft to 8 ft) from the stump. Most of the layers had been damaged by logging and lacked the vigor of the stump sprouts (3). Sapling and Pole Stages to Maturity Growth and Yield- Pacific yew, unlike most woody plants that grow in heavily shaded forest understories, often has a straight bole.

Although yew trees are reported to have typically fluted, ridged, and asymmetrical trunks, often with tightly spiraled grain (6,11,23,37,44), yew cutters in southwest Oregon reported that many yew trunks were round and unfluted above the base section, and straight-grained (7). Large limbs are common in the mid and upper bole. The crown tends to be ragged and lopsided. Pacific yew "reaches" for light by way of limbs that may be as long as the tree is tall. Young trees often have an umbrella-shaped crown of flat branches, and old trees have long drooping spray-like branches. Pacific yew is sometimes shrub-like, forming dense thickets. In western Montana, parts of Idaho, northeastern California, the Blue Mountains of eastern Oregon and southeastern Washington, and at high elevations throughout its range, the shrub form of yew often occurs in the absence of tree-size specimens (3,8,10,11,20,27,30,31,35,44,49,50).

In other areas, large tree-size yews may occasionally be found in or near yew shrub thickets (3). Whether the differences in size and form are genetic traits or the results of environment and stand history is not known. The needles of Pacific yew are dark green on the underside, two ranked, and spirally arranged on twigs. The bark is purplish, papery thin, and scalelike. New bark is rose red (6,19,22,40). The wood is fine grained, hard, and heavy: at 712 kg/m³ (about 44 lb/ft³) (8 percent moisture content), it is the heaviest of U.S. conifers, comparable in weight to high-density hardwoods such as ash, oak, and hard maple (46). Heartwood is red to brownish red, and sapwood is whitish yellow to bright yellow. Pacific yew grows slowly, taking about the same time to grow to 30 cm (12 in) in d.b.h. as other conifers in the same stand take to grow to several times that size. Height growth is correspondingly slow.

Trees larger than 50 cm (20 in) in d.b.h. and taller than 12 m (40 ft) are rare within most of the species' range: they account for less than 2 percent of the yew trees tallied on inventory plots on non-Federal land in California, Oregon, and Washington. The following tabulation shows average height by diameter class as determined from 55 Pacific yew trees randomly selected in Oregon and Washington (47): D.b.h 60 cm (24 in) 15 m (49 ft) Because of the slow growth of individual trees and because the species is typically found as an occasional tree in stands of other tree species, volumes and yields of Pacific yew are low. Stands with 125 yew trees/ha (50/acre) that are 20 cm (8 in) in d.b.h. and larger have been observed, but always in association with other species (3). The theoretical volume of yew wood in such stands could be as much as 140 m³/ha (2,000 ft³/acre), including the volume in main stems from ground level to tip.

The greatest volume of Pacific yew found in randomly located plots on non-Federal land in California, Oregon, and Washington was 28 m³/ha (400 ft³/acre) (47). These are gross volume estimates. Because heart rot is prevalent in large yew trees, net volume would be considerably less. In Idaho, analyses of increment cores and stem sections of yew trees from mature stands showed annual growth in diameter at 15 cm (6 in) above ground to range from 0.05 cm (0.02 in) to 0.25 cm (0.10 in). The following tabulation shows diameters by age class (1l): Age in years 125 22.9 cm (9.0 in) The largest known Pacific yew tree is found in a cool, moist valley in western Washington (28). Large yew trees are, however, more prevalent on somewhat drier sites with warm, moist winters.

Forty-seven percent of all the yew trees larger than 30 cm (12 in) tallied on inventory plots on non-Federal land in California, Oregon, and Washington were in a 4-county area in southwestern Oregon at mid to low elevations in the drier interior valleys and slopes between the Cascade and Coast Ranges, and in the Klamath Mountains (47). Although Pacific yew is sometimes damaged by heat, frost, and wind, especially after overstory trees have been removed (10 , 11,35,44), it can sometimes respond to release. On permanent plots in western Oregon measured 12 years apart, diameters of undamaged yew trees left after removal of overstory trees grew an average of 0.18 cm/yr (0-07 in/yr) and trees under dense overstories grew 0.06 cm (0.02 in) (47). The adaptation of Pacific yew to overstory removal is made possible through morphological changes in the needles-length, cuticle thickness, and deflection from the horizontal-and development of epicormic twigs (10,11).

Rooting Habit- The root system of Pacific yew is deep and wide-spreading (22). Reaction to Competition- Pacific yew is very tolerant of shade (1,11,44). It appears to require shade for establishment and can grow and develop under heavy forest canopies. On many sites, it is able to adapt to overstory removal (10,11), and large, old trees can be found that have been in the open much of their lives (3). Damaging Agents- Pacific yew is sensitive to damage from fire, and, where the overstory has been removed, it is sometimes damaged by exposure to the sun, wind, and cold (10,11,26,35,44). It resists damage from sulfur dioxide and was the least sensitive of 12 coniferous species to smelter fumes at Trail, British Columbia (26). Diseases of Pacific yew seedlings have not been studied, but Rhizoctonia solani, Phytophthora cinnamoni, and Pythium sp. have caused damping-off and seedling root rot in yews in the East. No serious leaf diseases have been reported.

Snow blights- Neopeckia coulteri and Herpotrichia juniperi- have caused localized damage, and four needle blights are caused by Macrophoma taxi, Mycosphaerella taxi, Phoma hystrella, and Sphaerulina taxi. A stem canker is caused by Diplodia taxi, and twig blights by P. hystrella and Physalopspora gregaria. Two root diseases- Armillaria ostoyae (obscura) and Phaeolus schweinitzii have been reported on Pacific yew in Idaho (26). Although seasoned heartwood of Pacific yew is extremely durable, large living Pacific yew trees often have heartrot or hollow boles (11,23). Many of the yew trees over 50 cm (20 in) d.b.h. tallied on non-Federal land in California, Oregon, and Washington could not be bored to determine age because of rotten or hollow trunks (47). Heartrot fungi infecting Pacific yew include Phellinus nigrolimitatus, P. pini, P. robustus, and Fomitopsis rosea (26).

Several insects cause damage to yews in the eastern United States, including Lecanium fletcheri (called Fletcher scale or taxus lecanium), Pseudococcus comstocki (Comstock mealybug), Dysmicoccus wistariae, Pseudococcus maritimus (grape mealybug), and Maladera castanea (Asiatic garden beetle) (2). No damage to Pacific yew in forested settings has been confirmed. Reported damage to Pacific yew foliage by budworms (Choristoneura spp.) in areas of heavy budworm infestation is thought to be heat or frost damage resulting from the defoliation of the overstory (5,41). Special Uses The wood of Pacific yew has been used for archery bows, canoe paddles, tool handles, gunstocks, boat decking, furniture, musical instruments, carved figurines, and miscellaneous novelty items. (In a recent western State gubernatorial election, campaign buttons were made of yew wood.) Japanese have used Pacific yew for ceremonial "Toko" poles, which they place next to entrances of their homes (6,19,23,29,44).

Pacific yew's resistance to decay makes it useful for fenceposts. Of seven northwest species tested for use as untreated fenceposts, Pacific yew was the second most durable, with an average service life of 25 years (33). In the mid-1980's Japanese purchasers paid $3,600 per thousand board feet (Scribner scale) for Pacific yew logs, mostly for wood carvings. In 1989, Japanese buyers agreed to pay $4,150 per thousand for grade 1 yew logs, and a Taiwanese buyer paid $6,100 (7). Among Native Americans, Saanich Tribal women used Pacific yew to remove underarm hair; Okanagans made a red paint from ground yew wood mixed with fish oil; several tribes smoked dried yew needles, which was said to cause dizziness; Haidas believed that women who ate yew berries would not conceive.

Yew was valued as an item of trade and used in making instruments for hunting, fishing, and warring; tools, such as mauls and splitting wedges; household utensils, such as bowls and spoons; and medicine for a broad range of ailments (23,29,44). Pacific yew is again being used for medicinal purposes. In the late 1960's, taxol-a complex compound extracted from yew bark-was identified as a possible anticancer agent (18,48). The National Cancer Institute (NCI) has found taxol to be one of the most promising of more than 120,000 plant compounds tested for anticancer properties. Taxol appears to be effective against a wide range of tumors, and good responses have been obtained in the treatment of refractory ovarian cancer (9,38). In 1988, the NCI acquired 27 700 kg (60,000 lb) of dried Pacific yew bark, collected from trees cut down in southwestern Oregon.

On average, one yew tree yielded 18 kg (40 lb) of green bark, which weighed about 9 kg (19 lb) dried (7). From the 27 700 kg of dried bark, about 4 kg (9 lb) of dry, crystalline taxol was extracted. Clinicians in several locations across the country have asked for increased supplies of taxol to expand tests to a broader range of cancer types. In January 1989, the NCI solicited another 27 700 kg of yew bark (9). The 27 700 kg of yew bark already collected and the second 27 700 kg ordered represent 6,000 to 7,000 trees. Most of these trees were cut or will be cut on Federal forest land where yew has not been inventoried. On non-Federal lands in California, Oregon, and Washington, where inventories have been made, there are an estimated 700,000 Pacific yew trees 28 cm (11 in) d.b.h. and larger, the size of most trees cut for bark collection.

Almost all the yew trees on non-Federal land are survivors of logging operations that removed the old-growth overstory (47). On Federal land where old-growth forests still exist, many more yew trees are thought to be present, but trees of the size needed to produce large quantities of bark are not abundant in most areas. An unknown but unquestionably significant percentage of the original yew resource has already been destroyed in logging. In the process of harvesting Douglas-fir and other timber species, mostly by clearcutting, yew trees were either cut or knocked over and broken up by machinery. Yew trees were seldom taken in primary logging operations, but some yew wood was later salvaged by firewood cutters and gleaners gathering wood for specialty products. Most of the yew trees that existed in logged areas were burned in slash-disposal fires. In many logged areas, the rootstocks have survived and resprouted, so, although the wood and bark of many yew trees were destroyed, there seems to have been little threat to the existence of the yew germ plasm. Continued or increased demand for yew bark for taxol production could further decrease a resource that has already been greatly reduced.

Attempts to synthesize taxol in the laboratory have failed, and prospects for success in the future are considered to be poor. The only known source of taxol now is yew bark. Taxol has been found in most of the several other species of Taxus that exist, but Pacific yew is the only one that is considered to be a practical source of quantities sufficient for clinical use (9,12). At least one private organization has begun to investigate alternative ways of producing taxol, through tissue culture and by growing vegetatively propagated seedlings in a controlled environment (7). The several species of yew in both the western and eastern hemispheres are thought to have poisonous seeds and foliage. Incidents of livestock poisoning by yew have been reported in Europe and North America. Conversely, in both Europe and North America, domestic and wild animals are known to browse yew foliage without ill effects. If and under what conditions yew foliage is poisonous are not known (13,14,22,32). Pacific yew is browsed by moose in the South Fork of the Clearwater River basin in Idaho, where the tree is considered critical to the animals' survival (36).

Pacific yew is also browsed heavily by elk and occasionally by deer in Oregon and Washington (20,23,30). Sprouts and epicormic branches that form in response to stand disturbance are favored by browsing animals. Repeatedly browsed yews in clearcut areas sometimes develop compact bushy crowns resembling the yew topiary of English gardens. Some limited use of T. brevifolia as an ornamental indicates it also has potential as a shade tree, for hedges, and for topiary (23,44). Genetics Pacific yew occurs in nature as a shrub or a tree, but whether the two forms are distinct subspecies, races, or varieties is not known. Three cultivars have been reported: cv erecta, a columnar form; cv nana, a dwarf form; and cv nutallii, a drooping form. A hybrid between Taxus brevifolia and T. cuspidata (Japanese yew) has been reported, but has no botanical standing. Pacific yew was originally classified as a variety of T.

baccata (European yew), which it closely resembles; some botanists grouped all seven of the currently recognized species of Taxus worldwide as varieties of T. baccata. Where different species grow near each other, interspecific hybrids frequently occur, lending support to the view that there is but one species (13,22,23,34,44). Further evidence of the close similarity of the species of Taxus is provided by bark analyses which show that most species contain taxol (9), and by an analysis of heartwood constituents of T. baccata, T. brevifolia, T. cuspidata, and T. floridana: the four species were found to be "chemically almost indistinguishable" (15) Literature Cited Baker, Frederick S. 1950. Principles of silviculture. McGraw-Hill, New York. 414 p. Baker, Whiteford L. 1972. Eastern forest insects. U.S. Department of Agriculture, Miscellaneous Publication 1175. Washington, DC. 642 p. Bolsinger, Charles L. Personal observation.

Brockway, Dale G., Christopher Topik, Miles A. Hemstrom, and William H. Emmingham. 1983. Plant association and management guide for the Pacific silver fir zone, Gifford Pinchot National Forest. R6-Ecol-130a-1983. USDA Forest Service, Pacific Northwest Region, Portland, OR. 122 p. Carolin, Val M. (retired). 1988. Personal communication. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. Collingwood, G. H., and Warren D. Brush. 1978. Knowing your trees. Revised and edited by Devereux Butcher. American Forestry Association, Washington, DC. 389 p. Connolly, Patrick. Personal communications. Yew Wood Industries, Portland, OR. (April 1988, December 1988, January 1989). Cooper, Stephen V., Kenneth E. Neiman, Robert Steele, and David W. Roberts. 1987. Forest habitat types of northern Idaho: a second approximation. USDA Forest Service, General Technical Report INT-236.

Intermountain Research Station, Ogden, UT. 135 p. Cragg, Gordon. Personal communications. National Cancer Institute, Bethesda, MD. (March, April, July 1988). Crawford, R. C. 1981. Response of Taxus brevifolia Nutt. (Pacific yew) following timber harvesting. p. 43. In Programs and Abstracts, fifty-fourth annual meeting of the Northwest Scientific Association, Oregon State University, Corvallis. Crawford, Rex Charles. 1983. Pacific yew community ecology in north-central Idaho with implications to forest land management. Thesis (Ph.D.). University of Idaho, Moscow. 109 P. Croom, Ed. 1989. Personal communication. School of Pharmacy, University of Mississippi, University. Dallimore, W., and A. Bruce Jackson. 1923. A handbook of coniferae including Ginkoaceae. Edward Arnold and Co., London. 570 p. Encyclopedia Britannica. 1966. Volume 23 (Vase to Zygote):889-890. William Benton, Chicago.

Erdtman, E., and K. Tsuno. 1969. Taxus heartwood constituents. Phytochemistry (8):931-932. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Society of American Foresters. Washington, DC. 148 p. Franklin, Jerry F., and C. T. Dyrness. 1973. Natural vegetation of Oregon and Washington. USDA Forest Service, General Technical Report PNW-8. Pacific Northwest Forest and Range Experiment Station, Portland, OR. 417 p. Fuchs, D. A., and R. K. Johnson. 1978. Cytological evidence that taxol, an antineoplastic agent from Taxus brevifolia, acts as a mitotic spindle poison. Cancer Treatments Reports 62(8):1219-1222. Green, George Rex. 1938. Trees of North America. Vol. 1. The conifers. Edwards Brothers, Inc., Ann Arbor, MI. 186 p. Hall, Frederick C. 1988.

Personal communication. USDA Forest Service, Pacific Northwest Region, Portland, OR. Hamilton, Ronald. 1988. Personal communication. USDA Forest Service, Intermountain Region, Ogden, UT. Harlow, William M., and Ellwood S. Harrar. 1958. Textbook of dendrology. 4th ed. McGraw-Hill, New York. 561 p. Hartzell, Hal, and Jerry Rust. 1983. Yew. Published by Hal Hartzell and Jerry Rust, Eugene, OR. 164 p. Hemstrom, Miles A., William H. Emmingham, Nancy M. Halverson, and others. 1982. Plant association and management guide for the Pacific silver fir zone, Mt. Hood and Willamette National Forests. R6-Ecol-100-1982a. USDA Forest Service, Pacific Northwest Region, Portland, OR, 104 p. Hemstrom, Miles A., Sheila E. Logan, and Warren Pavlat. 1985. Preliminary plant association and management guide, Willamette National Forest.

USDA Forest Service, Pacific Northwest Region, Portland, OR. 206 p. Hepting, George H. 1971. Diseases of forest and shade trees of the United States. U.S. Department of Agriculture, Agriculture Handbook 386. Washington, DC. 658 p. Hopkins, William E. 1988. Personal communication. USDA Forest Service, Pacific Northwest Region, Bend, OR. Hunt, Francis A. 1986. National register of big trees. American Forests 92(4):21-52. Jepson, Willis L. 1910. The silva of California. The University Press, Berkeley, CA. 480 p. Lesher, Robin. 1988. Personal communication. USDA Forest Service, Pacific Northwest Region, Olympia, WA. Long, Brian. 1988. Personal communication. State Lands Division, Missoula, MT. Martin, Alexander C., Herbert S. Zim, and Arnold L. Nelson. 1961. American wildlife and plants-a guide to wildlife food habits. Dover Publications, Inc., New York. 500 p.

Miller, Donald J. 1986. Service life of treated and untreated fence posts: 1985 post-farm report. Oregon State University Forest Research Laboratory, Research Paper 18. Corvallis, OR. 26 p. Munz, Philip A., and David E. Keck. 1970. A California flora. University of California Press, Berkeley. 1681 p. Pfister, Robert D., Bernard L. Kovalchick, Stephen F. Arno, and Richard C. Presby. 1977. Forest habitat types of Montana. USDA Forest Service, General Technical Report INT-34. Intermountain Forest and Range Experiment Station, Ogden, UT. 174 p. Pierce, John D. 1984. Shiras moose forage selection in relation to browse availability in north-central Idaho. Canadian Journal of Zoology 62(12):2404-2409. Preston, Richard J. 1976. North American trees. 3d ed. Iowa State University Press, Ames. 399 p. Rowinski, Eric K., Ross C.

Donehower, Neil B. Roseshein, and others. 1988. Phase II study of taxol in advanced ovarian epithelial malignancies. [Abstract]. The Johns Hopkins Oncology Center, Baltimore, MD. Rudolf, Paul 0. 1974. Taxus L. Yew. In Seeds of woody plants in the United States. p. 799-802. C. S. Schopmeyer, tech. coord. U.S. Department of Agriculture, Agriculture Handbook 450. Washington, DC. Sargent, Charles Sprague. 1933. Manual of the trees of North America. 2d ed. Houghton Mifflin, Boston and New York. 910 P. Sartwell, Charles. 1988. Personal communication. USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR. Slater, James R. 1978. Pinatae distribution in the State of Washington. Occasional Paper. Museum of Natural History, University of Puget Sound (51):694-709. Tacoma, WA. Sudworth, George B.

1908. Forest trees of the Pacific slope. U.S. Department of Agriculture, Washington, DC. 441 p. Taylor, Roy L., and Sylvia Taylor. 1981. Taxus brevifolia in British Columbia. In Davidsonia 12(4):89- 94. University of British Columbia. Vancouver, BC. Topik, Christopher, Nancy M. Halverson, and Dale G. Brockway. 1986. Plant association guide for the western hemlock zone, Gifford Pinchot National Forest. USDA Forest Service, R6- Ecol-230a-1986. Pacific Northwest Region, Portland, OR. 132 p. U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 1955. Wood Handbook. Agriculture Handbook 72. Washington, DC. 528 p. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. Forest inventory records, on file. Wani, M. C., H. L. Taylor, M. E. Wall, and others. 1971. Plant anti tumor agents. Part 6.

The isolation and structure of taxol, a novel anti leukemic and anti tumor agent from Taxus brevifolia. Journal of the American Chemical Society 93(9):2325-2327. Ward, Roger. 1988. Personal communication. USDA Forest Service, Nez Perce National Forest, Grangeville, ID. Wheeler, David. 1988. Personal communication. USDA Forest Service, Pacific Northwest Region, Grants Pass, OR. Taxus baccata (Common Yew, European Yew) Home » Taxus baccata (Common Yew, European Yew) Taxus baccata Thomas, P. Justification: The Common Yew (Taxus baccata) has a very extensive range throughout Europe and beyond. Exploitation and attempts at eradication are no longer current. Cultivated rather than wild populations are exploited for chemical compounds to produce Taxol® unlike the situation with other yew species. Expansion is observed in many woodlands in recent decades.

Previously published Red List assessments: 1998 – Lower Risk/least concern (LR/lc) Geographic Range [top] Range Description: Taxus baccata occurs in all European countries as well as those in the Caucasus, and from Turkey eastwards to northern Iran. In North Africa it occurs in Morocco and Algeria. Consequently its extent of occurrence is well in excess of the Red List thresholds for any threatened category.

Countries occurrence: Native: Albania; Algeria; Andorra; Armenia (Armenia, Nagorno-Karabakh); Austria; Azerbaijan (Nakhichevan); Belgium; Bulgaria; Czech Republic; Denmark; Estonia; Finland; France (Corsica); Georgia (Abkhaziya, Adzhariya); Germany; Gibraltar; Greece (Kriti); Guernsey; Hungary; Iran, Islamic Republic of; Ireland; Isle of Man; Italy (Sardegna, Sicilia); Jersey; Latvia; Liechtenstein; Luxembourg; Malta; Moldova; Monaco; Montenegro; Morocco; Netherlands; Norway; Poland; Portugal (Azores); Romania; Russian Federation (Chechnya, Dagestan, Ingushetiya, Kabardino-Balkariya, Kaliningrad, Karachaevo-Cherkessiya, Krasnodar, Severo-Osetiya, Stavropol); Serbia (Serbia); Spain (Baleares); Sweden; Switzerland; Turkey (Turkey-in-Europe); Ukraine (Krym); United Kingdom Additional data: Population [top] Population: The global population is increasing due to changed woodland management, which has become less intensified in many parts of Europe.

In Scandinavia, it may be expected to expand inland from coastal areas if the warming climate trend continues. Current Population Trend: Habitat and Ecology [top] Habitat and Ecology: Taxus baccata is capable of growing under (not entirely closed) canopy of beech (Fagus spp.) as well as other deciduous broad-leaved trees, but it will only develop to large trees in more open situations. In Switzerland, the richest area of Central Europe for yew, it forms a yew-beech wood on cool, steep marl slopes in the Jura and the foothills of the Alps up to 1,400 m a.s.l. (Ellenberg 1988). Under the evergreen Common Yew, nothing else will grow. In England, T. baccata is best developed on chalk downs - again on steep slopes - and can form extensive stands outside the beech woods invading down grassland. In much of Europe where the climate is less oceanic it survives better in mixed forests, coniferous as well as mixed broad-leaved-conifer forests, again mostly on limestone substrates, and often occupying rocky cliffs and slopes.

On acid soils yews perform less well under canopy and usually do not develop beyond a sapling stage in woods. Its northern limits in Scandinavia are determined by its sensitivity to severe frost. Its toxicity (all parts except the red arils around the seeds) prevent browsing by cattle and sheep, but not by rabbits and deer, as these animals have developed a level of immunity to the dangerous alkaloids. Apart from seed germination (dispersed by birds), T. baccata readily regenerates from stumps and roots (suckers); ancient hollow trees may rejuvenate constantly in this way. When planted, e.g. in church yards and cemeteries, soil pH seems unimportant; some of the largest and presumably oldest specimen trees in NW Europe, in particular Brittany (France) and the British Isles, are known from such locations and were planted probably since Celtic times Systems: Use and Trade [top] Use and Trade: In the Middle Ages the wood of Common Yew was very much in demand for long-bows and cross-bows and was exported from Switzerland to England.

Yews were also planted near sacred wells, early Christian churches, monasteries, and castles for symbolic/religious reasons as well as practical (military) ones. It still is one of the obligatory cemetery trees in NW and Central Europe. The hard, slow growing wood is used for gates, furniture, parquet floors, panelling, and is excellent for carving and wood turning as its contorted growth and 'burls' form intricate, vari-coloured patterns. For the same reasons yew does not provide timber suitable for construction. The toxicity to cattle and horses has led to extermination of Taxus baccata from many woodlands in past centuries, when almost all woodland served for grazing animals. Although of lower concentration than in some other species, its alkaloid taxanes, contained mostly in the leaves, yield a semi-synthesized anti-cancer drug similar to Taxol® and yew hedge clippings can still be sold to pharmaceutical companies. As an ornamental shrub or tree it reappeared in the formal gardens of the Baroque period, as it lends itself to clipped hedges and topiary of all shapes.

This horticultural interest has in turn led to the development of numerous cultivars, some of which have bright yellow arils around the seeds. Threats [top] Major Threat(s): Although in past centuries Yew has been 'persecuted' in much of Europe and it had become rare in many areas, with the changes in woodland management and use since the nineteenth century the species has made a remarkable come-back and is not in danger of extinction in the wild. Conservation Actions [top] Conservation Actions: Common Yew is present in numerous protected areas throughout its range. In Europe, several yew dominated communities are covered under the EU Habitats Directive. Additionally there are many societies in various countries devoted to yew conservation, especially older trees. Citation: Farjon, A. 2013. Taxus baccata. The IUCN Red List of Threatened Species 2013: e.T42546A2986660. . Downloaded on 13 January 2017. Disclaimer:

Question: Taxus is the generic name for which tree?
Answer: Yew