European yew tree ( Taxus baccata ), illustration
The yew trees ( Taxus ) form a genus of plants in the yew family (Taxaceae). The ten to eleven species are mainly found in the temperate areas of the northern hemisphere ; the European yew ( Taxus baccata ) is the only species native to Europe.
Yew species are evergreen shrubs or small to medium-sized trees . Young twigs initially have green to yellowish-green bark ; some bud scales can be seen at the bottom. Later the bark turns reddish-brown, a scaly, reddish-brown bark develops on older branches .
The needles are arranged in a spiral on the branch, but are parted so that they appear to be arranged in two rows. The straight, flexible needles can be straight or curved. They end in a small attached but not piercing point. The central vein protrudes on the top of the needles, on the bottom there are two light stripes with the stomata .
Yew species are usually dioeciously separated ( dioecious ): Male and female flowers are on separate plant specimens, occasionally they are single-sexed ( monoecious ). The male cones are spherical and yellowish. They have four to 16 sporophylls , each of which has two to nine sporangia.
The seeds ripen in the year of fertilization . Female plants produce red "fruits" in autumn that contain a single seed in the middle . The red, fleshy tissue surrounding the seed - the seed coat ( arillus ) - does not develop from the seed coat ( testa), but from the stem area of the ovule ( funiculus ). The cup-shaped aril shows different shades of red depending on the species. In this case one does not speak of a fruit (in the botanical sense), but of a seed coat (arillus), since by definition there can only be fruits in flowering plants .
The pollen spreads via the wind ( anemophilia ). The seeds are mainly spread by birds, which eat the fleshy seed coat and later excrete the seeds again ( endochory ). Germination takes place epigeously , there are two cotyledons.
Most species of yew, such as the European yew ( Taxus baccata ), contain very toxic ingredients such as taxin B. In particular, the Pacific yew ( Taxus brevifolia ) contains paclitaxel (Taxol), which is used to treat breast and ovarian cancer. Bark, needles and seeds are poisonous. However, the red seed coat does not contain any toxins. Cases of fatal poisoning by yew trees are known from humans, cattle and horses. The occurrence of ecdysterone has been described several times.
The yew species are mainly found in the temperate zone of the northern hemisphere. In the New World they still reach Mexico , Guatemala and El Salvador to the south . In Southeast Asia they are found in tropical mountain forests and cross the equator on Celebes . While they occur at lower altitudes in the north of their range, they reach altitudes of 3000 meters in the tropics.
The European yew ( Taxus baccata ) was originally widespread in Germany around the mountain regions. In 1568, Duke Albrecht informed the Imperial Council in Nuremberg that there were no more mature yew trees in all of Bavaria. The reason for this was that the English longbows were made from the wood of the yew trees . From Nuremberg , thousands of them were shipped to Antwerp as export hits in the past . The Paterzeller Eibenwald has been preserved as a small relic of the Eibenwald in the former monastery forest of Wessobrunn , as well as in the Eibenwald natural forest reserve in Gößweinstein . Other larger deposits are located in southern Lower Saxony near Bovenden north of Göttingen and in Thuringia in the Ibengarten near Dermbach in the Rhön , on Lengenberg west of Lutter (Eichsfeld) in the district of Heiligenstadt and in the nature reserve Dissau and Steinberg near Rudolstadt. The yew population on the Swiss Uetliberg is of European importance , where the city of Zurich even set up a yew nature trail.
Yew trees grow in the shrub layer of moist forests or form part of the crown layer.
The genus Taxus was established by Carl von Linné . The scientific generic name Taxus is etymologically derived from neo-Persian taχš for " crossbow , arrow" and ancient Greek τόξον for " arrow bow " (for which yew wood is particularly suitable) with (perhaps underlying both words) Scythian * taχša- connected as well as with the indefinable old Indian tree name takṣaka- .
The systematic delimitation of the species and varieties within the genus is difficult and the authors sometimes differ. Aljos Farjon distinguishes between the following types:
- European yew , also called common yew ( Taxus baccata L. )
- Pacific yew ( Taxus brevifolia Nutt. ): It is distributed in western North America from southeastern Alaska via the Canadian provinces of British Columbia and Alberta to the US states of Montana , Idaho , Oregon , Washington and California .
- Taxus calcicola L.M.Gao & Mich.Möller : It was first described in 2016 and occurs from southeastern Yunnan , northeastern and southwestern Guizhou to northern Vietnam (in Laocai , Son La , Hòa Bình and Hà Giang ).
- Canadian yew ( Taxus canadensis Marshall ): It is found in central to eastern North America from the Canadian provinces of southeastern Manitoba , Ontario , Québec , Prince Edward Island , New Brunswick , Nova Scotia , Newfoundland to the US states of Connecticut , Illinois , Indiana , Iowa , Kentucky , Maine , Massachusetts , Michigan , Minnesota , New Hampshire , New York , Ohio , Pennsylvania , Rhode Island , Tennessee , Vermont , Virginia , Wisconsin and West Virginia .
- Chinese yew ( Taxus chinensis (Pilg.) Rehd. ): It occurs in China.
- Taxus contorta handle. It occurs in Afghanistan , northern Pakistan , central to western Nepal , the Indian states of Himachal Pradesh , Jammu and Kashmir as well as Uttar Pradesh and southwest Tibet (only in the Jilong region).
Japanese yew ( Taxus cuspidata Sieb. & Zucc. ): There are two varieties.
- Taxus cuspidata sieve. & Zucc. var. cuspidata (Syn .: Cephalotaxus umbraculifera Sieb. ex Endl. , Taxus baccata var. microcarpa Trautv. , Taxus baccata var. cuspidata (Sieb. & Zucc.) Carr. , Taxus cuspidata var. microcarpa (Trautv.) Kolesn. , Taxus cuspidata var. Umbraculifera (Sieb. Ex Endl.) Makino , Taxus cuspidata var. Latifolia (Pilg.) Nakai ): It occurs in the Chinese provinces of Heilongjiang , eastern Jilin , Liaoning , Shaanxi , in Korea , Japan ( Hokkaido , Honshu, Kyushu , Shikoku ), on the Kuril Islands and in Russia's Far East in the Primorye region and Sakhalin .
- Taxus cuspidata var. Nana Rehder (Syn .: Taxus cuspidata f. Nana (Rehder) EHWilson ): It grows as a dwarf shrub and its needles do not give the impression of being arranged in two rows. Little is known about this variety. It occurs in Russia's Far East (Primorye and Sakhalin region) and on the Japanese island of Honshu .
- Florida yew ( Taxus floridana Nutt. Ex Chapman ): This rare endemic thrives in damp and shady locations in hardwood forests along the Appalachicola River at altitudes of 15 to 30 meters only in Florida.
- Taxus florinii Spjut : It was first described in 2007 and occurs in southwest Sichuan and northwest Yunnan. Some authors put it as a synonym for Taxus wallichiana .
- Mexican yew ( Taxus globosa Schltdl. ): It occurs from the Mexican states of Nuevo León , Tamaulipas , San Luis Potosí , Veracruz , Querétaro , Hidalgo , Tlaxcala , Puebla , Oaxaca via Guatemala and Honduras to El Salvador .
Himalayan yew ( Taxus wallichiana Zucc. ): There are several varieties:
- Taxus wallichiana var. Chinensis (Pilg.) Florin ( Syn .: Taxus baccata var. Chinensis Pilg. , Taxus chinensis (Pilg.) Rehder ): It is in northern Vietnam and in the Chinese provinces of Anhui , Fujian , Gansu , Guangxi , Guizhou , Hubei , Hunan , Shaanxi , Sichuan , Yunnan and Zhejiang .
- Taxus wallichiana var. Mairei (Lemée & H.Lev.) LKFu & Nan Li (Syn .: Taxus chinensis var. Mairei (Lemée & H.Lév.) WCCheng & LKFu , Taxus mairei Lemée & H.Lév. ): She is Widespread in northeast India , Laos (unsafe), Myanmar , Vietnam , Taiwan and the Chinese provinces of Anhui, Fujian, Gansu, Guangdong , Guangxi, Guizhou, Henan , Hubei, Hunan, Jiangxi , Shaanxi, Sichuan, Yunnan and Zhejiang.
- Taxus wallichiana Zucc. var. wallichiana (Syn .: Taxus contorta Griff. , Taxus yunnanensis W.C.Cheng & LKFu ): It is widespread in India, Nepal , Bhutan , Myanmar , Vietnam , Tibet and the Chinese provinces of Sichuan and Yunnan.
There are numerous crossings . The best-known cross is the hybrid yew ( Taxus × media Rehder ), a cross between Taxus baccata and Taxus cuspidata that originated in Massachusetts in 1900 . Their broad, columnar cultivated form 'Hicksii' is used relatively often in parks and gardens.
The wood of the European and Pacific yew, which is seldom commercially available, is relatively hard, very tough and elastic. It is mainly used for woodturning work, as well as veneer, the construction of musical instruments and, since ancient times, for the production of bows .
- Christopher J. Earle: Taxus Linnaeus 1753-Yew. In: The Gymnosperm Database. January 17, 2020, accessed on March 26, 2020 .
- Richard W. Spjut: Overview of the Genus Taxus (Taxaceae): The Species, Their Classification, and Female Reproductive Morphology. 2010. online.
- Liguo Fu, Nan Li, Robert R. Mill: Taxaceae. In: Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China. Volume 4: Cycadaceae through Fagaceae. Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 1999, ISBN 0-915279-70-3 . Taxus Linnaeus , p. 91 - online with the same text as the printed work.
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden / Boston 2010, ISBN 978-90-04-17718-5 , pp. 969-985 .
- Fred Hageneder et al .: The yew tree in a new light. A monograph of the genus Taxus with photos by Andy McGeeney. Verlag Neue Erde, Saarbrücken 2007, ISBN 978-3-89060-077-2 .
- Petra Mensing et al .: Monograph of the Taxaceae Family. (= Scientific wood monographs. Volume 4). Verlag Gartenbild Hansmann, Rinteln 2005.
- Liguo Fu, Nan Li, Robert R. Mill: Taxaceae. : In: Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China. Volume 4: Cycadaceae through Fagaceae. Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 1999, ISBN 0-915279-70-3 . Taxus Linnaeus , p. 91 - online with the same text as the printed work.
- Matthew H. Hils: Taxaceae Gray. In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico. Volume 2: Pteridophytes and Gymnosperms. Oxford University Press, New York and Oxford, 1993, ISBN 0-19-508242-7 . Taxus - online with the same text as the printed work.
- Christopher J. Earle: Taxus Linnaeus 1753 - Yew. In: The Gymnosperm Database. January 17, 2020, accessed on March 26, 2020 .
- R. Hänsel, K. Keller, H. Rimpler, G. Schneider: Hagers Handbook of Pharmaceutical Practice . tape 6 . Springer Verlag, 1994 ( limited preview in the Google book search).
- H. Hoffmeister, G. Heinrich, GB Staal, WJ van der Burg: On the occurrence of ecdysterone in yews. In: Naturwissenschaften , Volume 54, Issue 17, 1967, p. 471. PMID 5586986
- NJ De Souza, El Ghisalberti, HH Rees, TW Goodwin: Studies on insect moulting hormones: biosynthesis of ponasterone A and ecdysterone from [2-14C] mevalonate in Taxus baccata. In: Biochem. J. , Volume 114, Issue 4, 1969, pp. 895-896. PMID 5343810
- H.Meinhardt: yew deposits in Thuringia and problems of yew rejuvenation. (PDF; 607 kB) Bavarian State Institute for Forests and Forestry, 1994, accessed on March 21, 2017 .
- On the way to the yew trees on the Uetliberg. at www.stadt-zuerich.ch ; accessed on August 1, 2019.
- Alexandra Wehrle: District of Breisgau-Hochschwarzwald: Falkensteig: Eiben im Höllental: Rare tree is making a comeback. In: Badische Zeitung. April 22, 2015, accessed September 27, 2016 .
- Taxus at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed April 4, 2019.
- Helmut Genaust : Etymological Dictionary of Botanical Plant Names . 3. Edition. Birkhäuser , Basel / Boston / Berlin 1996, ISBN 3-7643-2390-6 , p. 631 f . ( taxícola. on p. 631 f in the Google book search).
- Alois Walde , Johann Baptist Hofmann : Latin Etymological Dictionary . 3. Edition. Carl Winter, Heidelberg 1954 ( taxus. P. 653. ).
- Systematics and identification key at worldbotanical.com .
- David J. de Laubenfels: Coniferales. In: Flora Malesiana. Series I, Volume 10, Kluwer Academic, Dordrecht 1988, pp. 337-453.
- Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 970.
- Walter Erhardt , Erich Götz, Nils Bödeker, Siegmund Seybold: The great zander. Encyclopedia of Plant Names. Volume 2: Types and Varieties. Eugen Ulmer, Stuttgart (Hohenheim) 2008, ISBN 978-3-8001-5406-7 .
- Jürg Hassler-Schwarz: The yew (Taxus baccata L.): A description with special consideration of the canton of Graubünden. An attempt to describe the tree species with its physical and mythical characteristics ..., Publisher: Jürg Hassler-Schwarz, 1999.
- Contributions to the yew / Bavarian State Institute for Forest and Forestry, Freising (Ed.): Reports from the Bavarian State Institute for Forest and Forestry. No. 10. Bavarian State Institute for Forests and Forestry. 1996.
- Michael Möller, Lian-Ming Gao, Robert R. Mill, Jie Liu, De-Quan Zhang, Ram Poudel, De-Zhu Li: A multidisciplinary approach reveals hidden taxonomic diversity in the morphologically challenging Taxus wallichiana complex. In: Taxon , Volume 62, Issue 6, 2013, pp. 1161–1177. doi : 10.12705 / 626.9
- Taxus cuspidata var. Nana in the IUCN Red List of Threatened Species 2019.1. Listed by: T. Katsuki, D. Luscombe, 2010. Retrieved May 4, 2019.
- Richard W. Spjut: Taxonomy and nomenclature of Taxus (Taxaceae). In: Journal of the Botanical Research Institute of Texas , Volume 1, Issue 1, 2007, p. 222. Full text PDF.
- Nick Gibbs: Encyclopedia Living with Wood . Fleurus Verlag, Cologne 2008, ISBN 978-3-89717-425-2 , p. 184-186 .