Content deleted Content added
m →top |
|||
| (32 intermediate revisions by 29 users not shown) | |||
Line 1:
{{Short description|
{{redirect|Tea plant|the unrelated evergreen plant|ti plant}}
{{Use dmy dates|date=March 2020}}
Line 12:
| species = sinensis
| authority = ([[Carl Linnaeus|L.]]) [[Otto Kuntze|Kuntze]]
|
|Camellia oleosa |(Loureiro) Rehder
* ''Camellia parvisepaloides'' Hung T. Chang & H. S. Wang.▼
|Camellia polyneura |Hung T.Chang, Y.J.Tan & P.S.Wang
* ''Camellia theifera'' Griffith▼
|Camellia waldeniae |S. Y. Hu
* ''Thea bohea'' L.▼
|Thea olearia |Loureiro ex Gomes
|Thea sinensis |L.
* ''Theaphylla cantonensis ''(Loureiro) Rafinesque▼
| synonyms_ref = <ref name=FOC />▼
}}}}
| range_map = Tea plants native range.jpg
| range_map_caption = Native range of ''Camellia sinensis''
}}
'''''Camellia sinensis''''' is a [[species]] of evergreen [[shrub]] or small [[tree]] in the [[flowering plant]] family [[Theaceae]]. Its leaves
[[White tea]], [[yellow tea]], [[green tea]], [[oolong]], [[dark tea]] (which includes [[pu-erh tea]]) and [[black tea]] are all harvested from one of two major varieties grown today, ''C. sinensis'' var. ''sinensis'' and ''C. s.'' var. ''assamica'',<ref>[https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=506801 ITIS Standard Report Page Camellia Sinensis] {{Webarchive|url=https://web.archive.org/web/20221119190457/https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=506801 |date=19 November 2022 }} retrieved 2009-03-28.</ref> but are [[Tea processing|processed]] differently to attain varying levels of [[oxidation]] with black tea being the most oxidized and
== Description ==▼
''Camellia sinensis'' is native to [[East Asia]], the [[Indian Subcontinent]], and [[Southeast Asia]], but it is today cultivated all around the world in tropical and subtropical regions. It is an evergreen [[shrub]] or small [[tree]] that is usually trimmed to below {{convert|2|m|ft|abbr=on}} when cultivated for its leaves. It has a strong [[taproot]]. The flowers are yellow-white, {{convert|2.5|–|4|cm|in|abbr=on}} in diameter, with seven or eight petals.▼
The [[genus|generic]] name ''Camellia'' is taken from the [[Latinized name]] of Rev. [[Georg Joseph Kamel|Georg Kamel]],<ref>{{cite book | vauthors = Stafleu FA, Cowan RS |date=1976–1988 |title= Taxonomic literature: A selective guide to botanical publications and collections with dates, commentaries and types | url = https://archive.org/details/taxonomicliterat41983staf | edition = 2nd | publisher = Bohn, Scheltema and Holkema | location= Utrecht|isbn=9789031302246 }}</ref> [[Society of Jesus|SJ]] (1661–1706), a [[Moravia]]n-born [[Jesuit]] lay brother, pharmacist, and missionary to the [[Philippines]].▼
[[File:Flower of Tea plant.jpg|thumb|Flower of tea plant]]▼
[[File:
The seeds of ''C. sinensis'' and ''[[Camellia oleifera|C. oleifera]]'' can be pressed to yield [[tea oil]], a sweetish seasoning and cooking oil that should not be confused with [[tea tree oil]], an [[essential oil]] that is used for medical and cosmetic purposes, and originates from the leaves of a different plant.▼
[[File:Camellia sinensis - Köhler–s Medizinal-Pflanzen-025.jpg|right|thumb|''C. sinensis'' plant, with cross-section of the flower (lower left) and seeds (lower right)]]▼
[[File:Camellia sinensis MHNT.BOT.2016.12.24.jpg|thumb|''C. sinensis'']]
The leaves are {{convert|4|–|15|cm|in|abbr=on}} long and {{convert|2|–|5|cm|in|abbr=on}} broad. Fresh leaves contain about 4% [[caffeine]], as well as related compounds including [[theobromine]].<ref>{{cite web| publisher = Purdue| url = http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html
In 2017, Chinese scientists sequenced the genome of ''C. s. var. assamica.''<ref>{{cite journal | vauthors = Xia EH, Zhang HB, Sheng J, Li K, Zhang QJ, Kim C, Zhang Y, Liu Y, Zhu T, Li W, Huang H, Tong Y, Nan H, Shi C, Shi C, Jiang JJ, Mao SY, Jiao JY, Zhang D, Zhao Y, Zhao YJ, Zhang LP, Liu YL, Liu BY, Yu Y, Shao SF, Ni DJ, Eichler EE, Gao LZ | display-authors = 6 | title = The Tea Tree Genome Provides Insights into Tea Flavor and Independent Evolution of Caffeine Biosynthesis | journal = Molecular Plant | volume = 10 | issue = 6 | pages = 866–877 | date = June 2017 | pmid = 28473262 | doi = 10.1016/j.molp.2017.04.002 | doi-access = free }}</ref> It contains about three billion base pairs, which was larger than most plants previously sequenced.<ref>{{Cite news|url=https://www.bbc.co.uk/news/science-environment-39747720|title=Secrets of tea plant revealed by science|last=Briggs|first=Helen|date=2017-05-02|work=BBC News|access-date=2017-05-02|language=en-GB|archive-date=6 August 2018|archive-url=https://web.archive.org/web/20180806051540/https://www.bbc.co.uk/news/science-environment-39747720|url-status=live}}</ref>▼
== Taxonomy ==
▲The [[genus|generic]] name ''Camellia'' is taken from the [[Latinized name]] of Rev. [[Georg Joseph Kamel|Georg Kamel]],<ref>{{cite book | vauthors = Stafleu FA, Cowan RS |date=1976–1988 |title= Taxonomic literature: A selective guide to botanical publications and collections with dates, commentaries and types | url = https://archive.org/details/taxonomicliterat41983staf | edition = 2nd | publisher = Bohn, Scheltema and Holkema | location= Utrecht|isbn=
[[Carl Linnaeus]] chose his name in 1753 for the genus to honor Kamel's contributions to botany<ref>{{Citation | date = 10 August 2003 | chapter-url = http://www.gol27.com/HistoryTeaBotanics.html | title = History of Tea | chapter = Botanics | quote = Georg Jeoseph Kamel, whose name in Latin was Camellus was missionary to the Philippines, died in Manilla in 1706. […] Camellias were named in posthumous honor of George Joseph Kamel by Carolus Linnæus | access-date = 5 February 2012 | archive-date = 9 January 2016 | archive-url = https://web.archive.org/web/20160109202742/http://www.gol27.com/HistoryTeaBotanics.html | url-status = dead }}.</ref> (although Kamel did not discover or name this plant, or any ''Camellia'',<ref>{{Citation | date = 10 August 2003 | chapter-url = http://www.gol27.com/HistoryTeaBotanics.html | title = History of Tea | chapter = Botanics | quote = It is speculated that he never saw a camellia | access-date = 5 February 2012 | archive-date = 9 January 2016 | archive-url = https://web.archive.org/web/20160109202742/http://www.gol27.com/HistoryTeaBotanics.html | url-status = dead }}.</ref> and Linnaeus did not consider this plant a ''Camellia'' but a ''Thea'').<ref>{{Citation | date = 10 August 2003 | chapter-url = http://www.gol27.com/HistoryTeaBotanics.html | title = History of Tea | chapter = Botanics | quote = The first edition of Linnaeus's Species Plantarum published in 1753 suggested calling the tea plant Thea sinensis... | first = Leonid | last = Golender | name-list-style = vanc | access-date = 5 February 2012 | archive-date = 9 January 2016 | archive-url = https://web.archive.org/web/20160109202742/http://www.gol27.com/HistoryTeaBotanics.html | url-status = dead }}</ref>
[[Robert Sweet (botanist)|Robert Sweet]] shifted all formerly ''Thea'' species to the genus ''Camellia'' in 1818.<ref>{{Citation | chapter-url = http://www.bgbm.fu-berlin.de/iapt/nomenclature/code/tokyo-e/Art_13.htm | quote = The generic names ''Thea'' L. (Sp. Pl.: 515. 24 Mai 1753), and ''Camellia'' L. (Sp. Pl.: 698. 16 August 1753; Gen. Pl., ed. 5: 311. 1754), are treated as having been published simultaneously on 1 May 1753. … the combined genus bears the name ''Camellia'', since Sweet (Hort. Suburb. Lond.: 157. 1818), who was the first to unite the two genera, chose that name, and cited ''Thea'' as a synonym | author = International Association for Plant Taxonomy | author-link = International Association for Plant Taxonomy | year = 2006 | title = International Code of Botanical Nomenclature (Vienna Code) | chapter = Article 13, example 3 | edition = electronic | access-date = 5 February 2012 | archive-date = 30 November 2011 | archive-url = https://web.archive.org/web/20111130193614/http://www.bgbm.fu-berlin.de/iapt/nomenclature/code/tokyo-e/Art_13.htm | url-status = live }}.</ref> The name ''sinensis'' means "from China" in [[Latin]].
Four varieties of ''C. sinensis'' are recognized.<ref name=FOC>{{cite book | first1 = Tianlu | last1 = Min | first2 = Bruce | last2 = Bartholomew | name-list-style = vanc | chapter-url = http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200014043 | title = Flora of China | chapter = 18. Theaceae | volume = 12 | access-date = 16 October 2011 | archive-date = 29 December 2022 | archive-url = https://web.archive.org/web/20221229180605/http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200014043 | url-status = live }}</ref> Of these, ''C. sinensis'' var. ''sinensis'' and ''C. s.'' var. ''assamica'' (JW Masters) Kitamura are most commonly used for tea, and ''C. s.'' var. ''pubilimba'' Hung T. Chang and ''C. s.'' var. ''dehungensis'' (Hung T. Chang & BH Chen) TL Ming are sometimes used locally.<ref name=FOC /> The Cambodia type tea (''C. assamica'' subsp. ''lasiocaly'') was originally considered a type of assam tea. However, later genetic work showed that it is a hybrid between Chinese small leaf tea and assam type tea.<ref>Wambulwa, MC, MK Meegahakumbura, R Chalo, ''et al''. 2016. Nuclear microsatellites reveal the genetic architecture and breeding history of tea germplasm of East Africa. ''Tree Genetics & Genomes, 12.''</ref>
Tea plants are native to East Asia, and probably originated in the borderlands of north Burma and southwestern China.<ref name="Yamamoto">{{cite book |last1 = Yamamoto |first1 = T |last2 = Kim |first2 = M |last3=Juneja |first3 = L R |year = 1997 |isbn = 978-0-8493-4006-2 |title = Chemistry and Applications of Green Tea |publisher = CRC Press |page = 4 |quote = For a long time, botanists have asserted the dualism of tea origin from their observations that there exist distinct differences in the morphological characteristics between Assamese varieties and Chinese varieties... Hashimoto and Shimura reported that the differences in the morphological characteristics in tea plants are not necessarily the evidence of the dualism hypothesis from the researches using the statistical cluster analysis method. In recent investigations, it has also been made clear that both varieties have the same chromosome number (n=15) and can be easily hybridised with each other. In addition, various types of intermediate hybrids or spontaneous polyploids of tea plants have been found in a wide area extending over the regions mentioned above. These facts may prove that the place of origin of ''Camellia sinensis'' is in the area including the northern part of the Burma, Yunnan, and Sichuan districts of China.}}</ref>
Line 66 ⟶ 84:
Given their genetic differences forming distinct [[clade]]s, Chinese Assam type tea (''C. s.'' var. ''assamica'') may have two different parentages – one being found in southern [[Yunnan]] ([[Xishuangbanna]], [[Pu'er City]]) and the other in western Yunnan ([[Lincang]], [[Baoshan, Yunnan|Baoshan]]). Many types of Southern Yunnan Assam tea have been hybridized with the closely related species ''[[Camellia taliensis]].'' Unlike Southern Yunnan Assam tea, Western Yunnan Assam tea shares many genetic similarities with Indian Assam type tea (also ''C. s.'' var. ''assamica''). Thus, Western Yunnan Assam tea and Indian Assam tea both may have originated from the same parent plant in the area where southwestern China, Indo-Burma, and Tibet meet. However, as the Indian Assam tea shares no [[haplotype]]s with Western Yunnan Assam tea, Indian Assam tea is likely to have originated from an independent domestication. Some Indian Assam tea appears to have hybridized with the species ''[[Camellia pubicosta]].''<ref name="Meegahakumbura 1">{{cite journal | last1 = Meegahakumbura | first1 = MK | last2 = Wambulwa | first2 = MC | last3 = Thapa | first3 = KK |display-authors=etal | year = 2016 | title = Indications for three independent domestication events for the tea plant (''Camellia sinensis'' (L.) O. Kuntze) and new insights into the origin of tea germplasm in China and India revealed by nuclear microsatellites | journal = PLOS ONE |volume=11 |issue=5|page=e0155369 |pmid= 27218820 |pmc=4878758 |doi= 10.1371/journal.pone.0155369 | bibcode = 2016PLoSO..1155369M | doi-access = free }}</ref><ref name="Meegahakumbura 2">{{cite journal |vauthors=Meegahakumbura MK, Wambulwa MC, Li MM, Thapa KK, Sun YS, Möller M, Xu JC, Yang JB, Liu J, Liu BY, Li DZ, Gao LM |display-authors=3 |date=2018|title= Domestication origin and breeding history of the tea plant (Camellia sinensis) in China and India based on nuclear microsatellites and cpDNA sequence data|journal=Frontiers in Plant Science |volume=8|page=2270 |pmid= 29422908 |pmc=5788969 |doi= 10.3389/fpls.2017.02270|doi-access=free }}</ref>
Assuming a generation of 12 years, Chinese small leaf tea is estimated to have diverged from Assam tea around 22,000 years ago
Chinese small leaf type tea was introduced into India in 1836 by the British and some Indian Assam type tea (e.g. [[Darjeeling tea]]) appear to be genetic hybrids of Chinese small leaf type tea, native Indian Assam, and possibly also closely related wild tea species.<ref>{{cite journal |last1=Wambulwa |first1=M. C. |last2=Meegahakumbura |first2=M. K. |last3=Chalo |first3=R. |last4=Kamunya |first4=S. |last5=Muchugi |first5=A. |last6=Xu |first6=J. C. |last7=Liu |first7=J. |last8=Li |first8=D. Z. |last9=Gao |first9=L. M. |title=Nuclear microsatellites reveal the genetic architecture and breeding history of tea germplasm of East Africa |journal=Tree Genetics & Genomes |date=2016 |volume=12 |issue=1 |pages=11 |doi=10.1007/s11295-015-0963-x|s2cid=15909964 }}</ref>
=== Cultivars ===
Hundreds,<ref>{{Cite news|url=https://worldoftea.org/cultivar-database/|title=Tea Cultivar Database
* Benifuuki<ref name=ijtc>{{cite web
| title = Identification of Japanese tea (Camellia sinensis) cultivars using SSR marker
| publisher = [[Food and Agriculture Organization]]
| url = http://agris.fao.org/agris-search/search.do?recordID=JP2008002305
| access-date = 1 November 2018
| archive-date = 1 November 2018
| archive-url = https://web.archive.org/web/20181101135900/http://agris.fao.org/agris-search/search.do?recordID=JP2008002305
| url-status = live
}}</ref>
* Fushun<ref name=vdat>{{cite web
| title = Varietal differences in the adaptability of tea [Camellia sinensis] cultivars to light nitrogen application
| publisher = [[Food and Agriculture Organization]]
| url = http://agris.fao.org/agris-search/search.do?recordID=JP2008003777
| access-date = 1 November 2018
| archive-date = 1 November 2018
| archive-url = https://web.archive.org/web/20181101135956/http://agris.fao.org/agris-search/search.do?recordID=JP2008003777
| url-status = live
}}</ref>
* Kanayamidori<ref name=ijtc />
* Meiryoku<ref name=vdat />
Line 87 ⟶ 113:
* Okumidori<ref name=vdat />
* Yabukita<ref name=vdat />
▲== Description ==
▲''Camellia sinensis'' is native to [[East Asia]], the [[Indian Subcontinent]], and [[Southeast Asia]], but it is today cultivated all around the world in tropical and subtropical regions. It is an evergreen [[shrub]] or small [[tree]] that is usually trimmed to below {{convert|2|m|ft|abbr=on}} when cultivated for its leaves. It has a strong [[taproot]]. The flowers are yellow-white, {{convert|2.5|–|4|cm|in|abbr=on}} in diameter, with seven or eight petals.
▲[[File:Flower of Tea plant.jpg|thumb|Flower of tea plant]]
▲The seeds of ''C. sinensis'' and ''[[Camellia oleifera|C. oleifera]]'' can be pressed to yield [[tea oil]], a sweetish seasoning and cooking oil that should not be confused with [[tea tree oil]], an [[essential oil]] that is used for medical and cosmetic purposes, and originates from the leaves of a different plant.
▲[[File:Camellia sinensis - Köhler–s Medizinal-Pflanzen-025.jpg|right|thumb|''C. sinensis'' plant, with cross-section of the flower (lower left) and seeds (lower right)]]
▲[[File:Camellia sinensis MHNT.BOT.2016.12.24.jpg|thumb|''C. sinensis'']]
▲The leaves are {{convert|4|–|15|cm|in|abbr=on}} long and {{convert|2|–|5|cm|in|abbr=on}} broad. Fresh leaves contain about 4% [[caffeine]], as well as related compounds including [[theobromine]].<ref>{{cite web| publisher = Purdue| url= http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html |title=Camellia sinensis |access-date=18 February 2008}}</ref> The young, light-green leaves are preferably harvested for tea production; they have short, white hairs on the underside. Older leaves are deeper green. Different leaf ages produce differing tea qualities, since their chemical compositions are different. Usually, the tip (bud) and the first two to three leaves are harvested for processing. This hand picking is repeated every one to two weeks.
▲In 2017, Chinese scientists sequenced the genome of ''C. s. var. assamica.''<ref>{{cite journal | vauthors = Xia EH, Zhang HB, Sheng J, Li K, Zhang QJ, Kim C, Zhang Y, Liu Y, Zhu T, Li W, Huang H, Tong Y, Nan H, Shi C, Shi C, Jiang JJ, Mao SY, Jiao JY, Zhang D, Zhao Y, Zhao YJ, Zhang LP, Liu YL, Liu BY, Yu Y, Shao SF, Ni DJ, Eichler EE, Gao LZ | display-authors = 6 | title = The Tea Tree Genome Provides Insights into Tea Flavor and Independent Evolution of Caffeine Biosynthesis | journal = Molecular Plant | volume = 10 | issue = 6 | pages = 866–877 | date = June 2017 | pmid = 28473262 | doi = 10.1016/j.molp.2017.04.002 | doi-access = free }}</ref> It contains about three billion base pairs, which was larger than most plants previously sequenced.<ref>{{Cite news|url=https://www.bbc.co.uk/news/science-environment-39747720|title=Secrets of tea plant revealed by science|last=Briggs|first=Helen|date=2017-05-02|work=BBC News|access-date=2017-05-02|language=en-GB}}</ref>
== Cultivation ==
{{Main|tea#Cultivation and harvesting|l1=Tea cultivation}}
''Camellia sinensis'' is mainly cultivated in tropical and subtropical climates, in areas with at least 127 cm (50 in) of rainfall a year. Tea plants prefer a rich and moist growing location in full to part sun, and can be grown in [[hardiness zone]]s
Tea plants will grow into a tree if left undisturbed, but cultivated plants are pruned to waist height for ease of plucking. Two principal varieties are used, the small-leaved Chinese variety plant (''C. s. sinensis'') and the large-leaved Assamese plant (''C. s. assamica''), used mainly for black tea.
Line 110 ⟶ 124:
The Chinese plant is a small-leafed bush with multiple stems that reaches a height of some {{convert|3|m|ft|abbr=on}}. It is native to southeast China. The first tea plant variety to be discovered, recorded, and used to produce tea dates back 3,000 years ago; it yields some of the most popular teas.
''C. s.'' var. ''waldenae'' was considered a different species, ''C. waldenae'' by SY Hu,<ref name="ICS">{{Citation|url=http://www.uniklinik-saarland.de/med_fak/physiol2/camellia/register/species/spec_rs.htm |publisher=Uniklinik Sårland |place=DE |title=The International Camellia Society (ICS) |url-status=dead |archive-url=https://web.archive.org/web/20060821182008/http://www.uniklinik-saarland.de/med_fak/physiol2/camellia/register/species/spec_rs.htm |archive-date=21 August 2006 }}</ref> but it was later identified as a variety of ''C. sinensis''.<ref>{{cite journal | vauthors = Ming TL | year = 1992 | title = A revision of Camellia sect. Thea | journal = Acta Botanica Yunnanica | volume = 14 | issue = 2 | pages =
=== Indian teas ===
Three main kinds of tea are produced in India:
* [[Assam tea|Assam]], from the var. ''assamica'' plant, comes from the near sea-level heavily forested northeastern section of India, the state of [[Assam]]. Tea from here is rich and full-bodied. The first tea
* [[Darjeeling tea|Darjeeling]], from the var. ''sinensis'' plant, is from the cool and wet [[Darjeeling]] highland region, tucked in the foothills of the [[Himalayas]]. Tea plantations could be at altitudes as high as {{convert|2200|m|ft|abbr=on}}. The tea is delicately flavored, and considered to be one of the finest teas in the world. The Darjeeling plantations have three distinct harvests, termed 'flushes', and the tea produced from each flush has a unique flavor. First (spring) flush teas are light and aromatic, while the second (summer) flush produces tea with a bit more bite. The third, or autumn flush gives a tea that is lesser in quality.
* [[Nilgiri tea|Nilgiri]] is from a southern region of India almost as high as Darjeeling. Grown at elevations between {{convert|1000 and 2500|m|ft|abbr=on}}, Nilgiri teas are subtle and rather gentle, and are frequently blended with other, more robust teas.{{citation needed|date=December 2014}}
Line 121 ⟶ 135:
=== Pests and diseases ===
{{Main|List of tea diseases}}
Tea leaves are eaten by some [[herbivore]]s, such as the [[caterpillar]]s of the [[willow beauty]] (''Peribatodes rhomboidaria''), a [[geometer moth]].
== Health effects ==
{{Main|Health effects of tea}}
Although health benefits have been assumed throughout the history of using tea as a common beverage, no high-quality evidence shows that tea confers significant benefits.<ref name="medline">{{cite web|url=https://www.nlm.nih.gov/medlineplus/druginfo/natural/997.html|title=Black tea|publisher=MedlinePlus, US National Library of Medicine|date=30 November 2017|access-date=27 February 2018|archive-date=5 July 2016|archive-url=https://web.archive.org/web/20160705113528/https://www.nlm.nih.gov/medlineplus/druginfo/natural/997.html|url-status=live}}</ref><ref name="nccih">{{cite web|title=Green tea|url=https://nccih.nih.gov/health/greentea|publisher=National Center for Complementary and Integrative Health, US National Institutes of Health|access-date=27 February 2018|date=30 November 2016|archive-date=20 March 2015|archive-url=https://web.archive.org/web/20150320021603/https://nccih.nih.gov/health/greentea|url-status=live}}</ref> In [[clinical research]] over the early 21st century, tea has been studied extensively for its potential to lower the risk of [[human diseases]], but none of this research is conclusive as of 2017.<ref name=medline/>
== Biosynthesis of caffeine ==
[[Caffeine]], a molecule produced in ''C. sinensis'', functions as a [[secondary metabolite]] and acts as a natural [[pesticide]]: it can paralyze and kill herbivorous insects feeding on the plant.<ref name="insecticide">{{cite journal | vauthors = Nathanson JA | s2cid = 42711016 | title = Caffeine and related methylxanthines: possible naturally occurring pesticides | journal = Science | volume = 226 | issue = 4671 | pages =
[[File:Caffeine synthesis in c. sinensis.png|thumb|Biochemical pathway detailing caffeine synthesis in ''C. sinensis'']]
Line 155 ⟶ 168:
File:Epigallocatechin gallate structure.svg|(–)-[[Epigallocatechin gallate]]
File:Epicatechin gallate.svg|(–)-[[Epicatechin gallate]]
File:(–)-Epicatechin.svg|(–)-[[Epicatechin]]<ref>{{cite book | editor-first1 = Joseph E. | editor-last1 = Pizzorno | editor-first2 = Michael T. | editor-last2 = Murray | name-list-style = vanc | title = Textbook of Natural Medicine | date = 2012 | publisher = Churchill Livingstone | location = Edinburgh | isbn = 978-1-4377-2333-5 |
</gallery>
Line 162 ⟶ 175:
== External links ==
{{Commons
{{Wikispecies|Camellia sinensis}}
* {{ITIS |id=506801 |taxon=''Camellia sinensis'' |access-date=16 February 2006}}
| |||