Taxus cuspidata

File:八戸駅前のイチイ20240927-P1057460.jpg]]

In Japan, the tree is known as ichi'i (一位), meaning "first rank". This is because first rank courtiers carried shaku scepters made of yew. Other Japanese names include jakunoki, araragi, and onko. In the Ainu language, it is called rarmani.

In China, it is called dongbei hongdoushan (東北紅豆杉 "northeastern red bean fir"), zishan (紫杉 "purple fir"), or chi bo song (赤柏松 "red cypress-pine").

It is an evergreen tree or large shrub growing to 10–18 m tall, with a trunk up to 60 cm diameter. The 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 flattish rows either side of the stem except on erect leading shoots where the spiral arrangement is more obvious.

The seed cones are highly modified, each cone containing a single seed 4–8 mm long partly surrounded by a modified scale which develops into a soft, bright red berry-like structure called an aril, 8–12 mm long and wide and open at the end. The arils are mature 6–9 months after pollination.

Taxus cuspidata 2 (Hryshko National Botanical Garden, Kiev).jpg

Taxus cuspidata Cis japoński 2020-08-05 01.jpg|Closeup of the leaves

Taxus cuspidata IMG 4635.jpg|Berries

Japanese Yew Taxus cuspidata Bark 3008px.jpg|Rough bark

File:船通山のイチイ01.jpg]]

Japanese yew is a long-lived tree. Individual trees from Sikhote-Alin are known to have been 1,000 years old.{{cite web |language=ru |url=http://adm.khv.ru/invest2.nsf/pages/ru/rehabcentre.htm |title=Памятник природы "Сихотэ - Алинь". Центр реабилитации диких животных "УТЕС" |trans-title=The nature monument "Sikhote - Alin". Center for the rehabilitation of wild animals "UTES" |website=Туристические комплексы[Tourist complexes] |url-status=dead |archive-url=https://web.archive.org/web/20070929092614/http://adm.khv.ru/invest2.nsf/pages/ru/rehabcentre.htm |archive-date=2007-09-29}}

One specimen in Tottori, Japan, known as Sentsūzan-no-Ichii ("Yew of Mount Sentsū") is estimated at 2,000 years old.{{Cite book|author=鳥取県教育委員会社会教育課 |title=鳥取県文化財調査報告書第二・三集 |publisher=鳥取県教育委員会社会教育課 |year=1963 |page=114 |isbn=}}

File:Taxus cuspidata IMG 4700.jpgs]]

The entire yew bush, except the aril (the red flesh of the berry covering the seed), is toxic due to a group of chemicals called taxine alkaloids. Their cardiotoxicity is well known and act via calcium and sodium channel antagonism, causing an increase in cytoplasmic calcium currents of the myocardial cells. The seeds contains the highest concentrations of these alkaloids.{{Cite book |title=Toxic plants and other natural toxicants|date=1998|publisher=CAB International|last1=Garland|first1=Tam|last2=Barr|first2=A. Catherine |others=International Symposium on Poisonous Plants (5th : 1997 : Texas) |isbn=0851992633|location=Wallingford, England|oclc=39013798}}{{Cite journal|last1=Alloatti|first1=G.|last2=Penna|first2=C.|last3=Levi|first3=R.C.|last4=Gallo|first4=M.P.|last5=Appendino|first5=G.|last6=Fenoglio|first6=I.|date=1996|title=Effects of yew alkaloids and related compounds on guinea-pig isolated perfused heart and papillary muscle|journal=Life Sciences|volume=58|issue=10|pages=845–854 |pmid=8602118 |doi=10.1016/0024-3205(96)00018-5}} If any leaves or seeds of the plant are ingested, urgent medical advice is recommended, as well as observation for at least 6 hours after the point of ingestion.{{Cite web | url=http://www.npis.org/toxbase.html | title=TOXBASE - National Poisons Information Service | access-date=2019-09-05 | archive-date=2020-11-20 | archive-url=https://web.archive.org/web/20201120023000/https://www.npis.org/Toxbase.html | url-status=dead }}{{cite web |url=https://pfaf.org/user/plant.aspx?LatinName=Taxus+baccata |title=Plants for a Future Taxus baccata |access-date=2019-07-17}} The most cardiotoxic taxine is Taxine B followed by Taxine A; Taxine B also happens to be the most common alkaloid in the Taxus species.{{Cite journal|last1=Smythies|first1=J.R.|last2=Benington |first2=F.|last3=Morin|first3=R.D.|last4=Al-Zahid |first4=G.|last5=Schoepfle|first5=G.|date=1975|title=The action of the alkaloids from yew (Taxus baccata) on the action potential in the Xenopus medullated axon|journal=Experientia|volume=31|issue=3|pages=337–338|doi=10.1007/bf01922572|pmid=1116544|s2cid=8927297}}{{Cite journal|last1=Wilson|first1=Christina R.|last2=Sauer|first2=John-Michael|last3=Hooser|first3=Stephen B.|date=2001|title=Taxines: a review of the mechanism and toxicity of yew (Taxus spp.) alkaloids|journal=Toxicon|volume=39|issue=2–3|pages=175–185|doi=10.1016/s0041-0101(00)00146-x|pmid=10978734 |bibcode=2001Txcn...39..175W }}

File:Taxine B.png

Yew poisonings are relatively common in both domestic and wild animals who consume the plant accidentally.{{Cite web|url=https://www.promedmail.org/post/4789644|access-date=25 January 2016|date=24 January 2016|title=JAPANESE YEW PLANT POISONING - USA: (IDAHO) PRONGHORN ANTELOPE|publisher=ProMED-mail}}{{Cite web|url=https://www.promedmail.org/post/20110222.0578|access-date=25 January 2016|date=22 February 2011|title=PLANT POISONING, CERVID - USA: (ALASKA) ORNAMENTAL TREE, MOOSE|publisher=ProMED-mail}}{{Cite journal|last1=Tiwary|first1=Asheesh K.|last2=Puschner|first2=Birgit|last3=Kinde|first3=Hailu|last4=Tor |first4=Elizabeth R.|date=May 2005|title=Diagnosis of Taxus (yew) poisoning in a horse|journal=Journal of Veterinary Diagnostic Investigation|volume=17|issue=3|pages=252–255>|doi=10.1177/104063870501700307 |pmid=15945382|doi-access=free}} The taxine alkaloids are absorbed quickly from the intestine and in high enough quantities can cause death due to general cardiac failure, cardiac arrest, or respiratory failure.{{Cite book |title=Poisonous plants of California|date=1986|publisher=University of California Press|location=Berkeley|last1=Fuller|first1=Thomas C.|last2=McClintock|first2=Elizabeth M.|isbn=0520055683|oclc=13009854}} Taxines are also absorbed efficiently via the skin and Taxus species should thus be handled with care and preferably with gloves.Mitchell, A. F. (1972). Conifers in the British Isles. Forestry Commission Booklet 33. Taxus baccata leaves contain approximately 5 mg of taxines per 1g of leaves. The estimated (i.e. not by any means a fact) lethal dose (LD_min) of Taxus baccata leaves is 3.0-6.5 mg/kg body weight for humans{{Cite book|title=Taxaceae. In The Medicinal and Poisonous Plants of Southern and Eastern Africa|pages=1019–1022|date=1962|publisher=Livingston|location=Edinburgh, UK|last1=Watt|first1=J.M.|last2=Breyer-Brandwijk|first2=M.G.}} There is currently no known antidotes for yew poisoning, but drugs such as atropine have been used to treat the symptoms.{{Cite book|title=Veterinary Toxicology|pages=947–954|date=2018|publisher=Elsevier|last1=Wilson|first1=Christina R.|last2=Hooser |first2=Stephen B.|isbn=9780128114100|doi=10.1016/b978-0-12-811410-0.00066-0}} Taxine remains in the plant all year, with maximal concentrations appearing during the winter. Dried yew plant material retains its toxicity for several months and even increases its toxicity as the water is removed,{{cite web|title=Yew|url=http://www.provet.co.uk/lorgue/5a92fa3.htm|publisher=Provet|access-date=23 March 2013|archive-date=2 December 2013|archive-url=https://web.archive.org/web/20131202225310/http://www.provet.co.uk/lorgue/5a92fa3.htm|url-status=dead}} fallen leaves are also toxic.{{Cite web|url=http://www.fetoc.es/toxicologianet/pages/x/x19/05f.htm|title=Intoxicación por tejo|last=|first=|date=|website=|publisher=|access-date=}} Although poisoning usually occurs when leaves of yew trees are eaten, in at least one case a victim inhaled sawdust from a yew tree.{{Cite journal|last1=José Luis Hernández Hernández|last2=Fernando Quijano Terán|last3=Jesús González Macías|year=2010|title=Intoxicación por tejo|journal=Medicina Clínica|volume=135|issue=12|pages=575–576|doi=10.1016/j.medcli.2009.06.036|pmid=19819481}}

The following book made it clear that it is very difficult to measure taxine alkaloids and that this is a major reason as to why different studies show different results.{{Cite book|title=Veterinary Toxicology: Poisonous plants, Taxaceae|edition=3rd|pages=276–277|date=1988|publisher=Baillière, Tindall & Cassell|location=London|last1=Clarke|first1=E.G.C.|last2=Clarke|first2=M.L.}}

Minimum lethal dose, oral LD_min for many different animals were tested:

• Chicken 82.5 mg/kg
• Cow 10.0 mg/kg
• Dog 11.5 mg/kg
• Goat 60.0 mg/kg
• Horse 1.0–2.0 mg/kg
• Pig 3.5 mg/kg
• Sheep 12.5 mg/kg

Several studies[http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+3541 TAXINE - National Library of Medicine HSDB Database, section "Animal Toxicity Studies"] have found taxine {{LD50}} values under 20 mg/kg in mice and rats.

For symptoms of human toxicity see Taxine alkaloids

Male and monoecious yews in this genus release toxic pollen, which can cause the mild symptoms see Taxine alkaloids. The pollen are also a trigger for asthma. These pollen grains are only 15 microns in size, and can easily pass through most window screens.{{Cite web|url=http://www.saps.org.uk/pollen/index2.htm|title=Pollen images in size order|website=www.saps.org.uk|access-date=2017-04-13|archive-date=2021-05-13|archive-url=https://web.archive.org/web/20210513100048/https://www.saps.org.uk/pollen/index2.htm|url-status=dead}}

Taxus cuspidata is a source of taxoleic acid.

The tree is widely grown in eastern Asia and eastern North America as an ornamental plant.

File:Japanese Yew in Tokuge, Japan.jpg|Outside a Shinto shrine in Fujisaki, Aomori

File:Japanese Yew bonsai, 2011-05-29.jpg|As bonsai

File:Taxus cuspidata IMG 4640.jpg|On a sidewalk

{{Reflist}}

{{Commons|Taxus cuspidata}}

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cuspidata

Category:Trees of China

Category:Trees of Korea

Category:Trees of Japan

Category:Trees of Siberia

Category:Plants used in bonsai

Category:Plants described in 1846

Category:Taxa named by Philipp Franz von Siebold

Category:Taxa named by Joseph Gerhard Zuccarini