''Camellia sinensis'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of evergreen

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

or small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

in the

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

family

Theaceae Theaceae (), the tea family, is a family (biology), family of flowering plants comprising shrubs and trees, including the economically important tea plant, and the ornamental camellias. It can be described as having from seven to 40 genus, genera ...

. Its leaves and leaf buds are used to produce the popular beverage,

tea Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of '' Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of southwestern China and northe ...

. Common names include tea plant, tea shrub, and tea tree (not to be confused with ''

Melaleuca alternifolia ''Melaleuca alternifolia'', commonly known as tea tree, is a species of tree or tall shrub in the myrtle family, Myrtaceae. Endemic to Australia, it occurs in southeast Queensland and the north coast and adjacent ranges of New South Wales wher ...

'', the source of

tea tree oil Tea tree oil, also known as melaleuca oil, is an essential oil with a fresh camphoraceous odor and a colour that ranges from pale yellow to nearly colourless and clear. It is derived from the leaves of the tea tree, ''Melaleuca alternifolia'', ...

, or the genus ''

Leptospermum ''Leptospermum'' is a genus of shrubs and small trees in the myrtle family Myrtaceae commonly known as tea trees, although this name is sometimes also used for some species of ''Melaleuca''. Most species are endemic to Australia, with the greate ...

'' commonly called tea tree).

White tea White tea may refer to one of several styles of tea which generally feature young or minimally processed leaves of the ''Camellia sinensis'' plant. Currently there is no generally accepted definition of white tea and very little internationa ...

yellow tea Yellow tea can refer to Chinese ''huángchá'' () and Korean ''hwangcha'' (). Chinese ''huangcha'' It is an increasingly rare and expensive variety of tea. The process for making yellow tea is similar to that of green but with an added step ...

green tea Green tea is a type of tea that is made from '' Camellia sinensis'' leaves and buds that have not undergone the same withering and oxidation process which is used to make oolong teas and black teas. Green tea originated in China, and since the ...

oolong Oolong (, ; (''wūlóngchá'', "dark dragon" tea)) is a traditional semi-oxidized Chinese tea ('' Camellia sinensis)'' produced through a process including withering the plant under strong sun and oxidation before curling and twisting.Zhonggu ...

, dark tea (which includes

pu-erh tea ''Pu'er'' or ''pu-erh'' is a variety of fermented tea traditionally produced in Yunnan Province, China. In the context of traditional Chinese tea production terminology, fermentation refers to microbial fermentation (called 'wet piling'), an ...

) and

black tea Black tea, also translated to red tea in various East Asian languages, is a type of tea that is more oxidized than oolong, yellow, white and green teas. Black tea is generally stronger in flavour than other teas. All five types are made from ...

are all harvested from one of two major varieties grown today, ''C. sinensis'' var. ''sinensis'' and ''C. s.'' var. ''assamica'', but are processed differently to attain varying levels of

oxidation Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...

with black tea being the most oxidized and green being the least. Kukicha (

twig A twig is a thin, often short, branch of a tree or bush. The buds on the twig are an important diagnostic characteristic, as are the abscission scars where the leaves have fallen away. The color, texture, and patterning of the twig bark are ...

tea) is also harvested from ''C. sinensis'', but uses twigs and stems rather than leaves.

Nomenclature and taxonomy

The

generic Generic or generics may refer to: In business * Generic term, a common name used for a range or class of similar things not protected by trademark * Generic brand, a brand for a product that does not have an associated brand or trademark, other ...

name ''Camellia'' is taken from the

Latinized name Latinisation (or Latinization) of names, also known as onomastic Latinisation, is the practice of rendering a ''non''-Latin name in a Latin style. It is commonly found with historical proper names, including personal names and toponyms, and in t ...

of Rev. Georg Kamel, SJ (1661–1706), a

Moravia Moravia ( , also , ; cs, Morava ; german: link=yes, Mähren ; pl, Morawy ; szl, Morawa; la, Moravia) is a historical region in the east of the Czech Republic and one of three historical Czech lands, with Bohemia and Czech Silesia. The me ...

n-born

Jesuit , image = Ihs-logo.svg , image_size = 175px , caption = ChristogramOfficial seal of the Jesuits , abbreviation = SJ , nickname = Jesuits , formation = , founders ...

lay brother, pharmacist, and missionary to the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

chose his name in 1753 for the genus to honor Kamel's contributions to botany (although Kamel did not discover or name this plant, or any ''Camellia'', and Linnaeus did not consider this plant a ''Camellia'' but a ''Thea''). Robert Sweet shifted all formerly ''Thea'' species to the genus ''Camellia'' in 1818. The name ''sinensis'' means "from China" in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

. Four varieties of ''C. sinensis'' are recognized. 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. 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. Tea plants are native to East Asia, and probably originated in the borderlands of north Burma and southwestern China. * Chinese (small leaf) tea 'C. sinensis'' var. ''sinensis''* Chinese Western Yunnan Assam (large leaf) tea 'C. sinensis'' var. ''assamica''* Indian Assam (large leaf) tea 'C. sinensis'' var. ''assamica''* Chinese Southern Yunnan Assam (large leaf) tea 'C. sinensis'' var. ''assamica'' Chinese (small leaf) tea may have originated in southern China possibly with hybridization of unknown wild tea relatives. However, since no wild populations of this tea are known, the precise location of its origin is speculative. Given their genetic differences forming distinct

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

s, Chinese Assam type tea (''C. s.'' var. ''assamica'') may have two different parentages – one being found in southern

Yunnan Yunnan , () is a landlocked Provinces of China, province in Southwest China, the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is ...

(

Xishuangbanna Xishuangbanna, Sibsongbanna or Sipsong Panna ( Tham: , New Tai Lü script: ; ; th, สิบสองปันนา; lo, ສິບສອງພັນນາ; shn, သိပ်းသွင်ပၼ်းၼႃး; my, စစ်ဆောင်� ...

Pu'er City Pu'er is a prefecture-level city in southern Yunnan Province, China. The urban administrative center of Pu'er is Simao District, which is also the former name of the prefecture-level city itself. A major downturn in the price of tea in 2007 caus ...

) and the other in western Yunnan (

Lincang Lincang () is a prefecture-level city located in the southwest of Yunnan province, People's Republic of China. History Lincang was previously called Baihuai during the Shang dynasty. On December 26, 2003, the state council approved the cancell ...

, Baoshan). Many types of Southern Yunnan Assam tea have been hybridized with the closely related species ''

Camellia taliensis ''Camellia taliensis'' (also known as Yunnan large leaf varietal tea, wild tea, Dali tea, Yunnan broad tea, and others; 大理茶) is a species of evergreen shrub or small tree whose leaves and leaf buds are used to produce tea. It is of the ge ...

.'' 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 A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. Many organisms contain genetic material ( DNA) which is inherited from two parents. Normally these organisms have their DNA or ...

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.'' Assuming a generation of 12 years, Chinese small leaf tea is estimated to have diverged from Assam tea around 22,000 years ago, while Chinese Assam tea and Indian Assam tea diverged 2,800 years ago. This divergence tea would correspond to the last

glacial maximum An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

. Chinese small leaf type tea was introduced into India in 1836 by the British and some Indian Assam type tea (e.g.

Darjeeling tea Darjeeling tea is a tea made from ''Camellia sinensis var. sinensis'' that is grown and processed in Darjeeling or Kalimpong Districts in West Bengal, India. Since 2004, the term ''Darjeeling tea'' has been a registered geographical indication ...

) appear to be genetic hybrids of Chinese small leaf type tea, native Indian Assam, and possibly also closely related wild tea species.

Cultivars

Hundreds, if not thousands of

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

s of ''C. sinensis'' are known. Some Japanese cultivars include: * Benifuuki * Fushun * Kanayamidori * Meiryoku * Saemidori * Okumidori * Yabukita

Description

''Camellia sinensis'' is native to

East Asia East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea and ...

, the

Indian Subcontinent The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...

, and

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

, but it is today cultivated all around the world in tropical and subtropical regions. It is an evergreen

or small

that is usually trimmed to below when cultivated for its leaves. It has a strong

taproot A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproo ...

. The flowers are yellow-white, in diameter, with seven or eight petals. Flower of Tea plant

The seeds of ''C. sinensis'' and '' C. oleifera'' can be pressed to yield

tea oil Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of ''Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of southwestern China and northe ...

, a sweetish seasoning and cooking oil that should not be confused with

, an

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

that is used for medical and cosmetic purposes, and originates from the leaves of a different plant. Camellia sinensis - Köhler–s Medizinal-Pflanzen-025

Camellia sinensis - Köhler–s Medizinal-Pflanzen-025

The leaves are long and broad. Fresh leaves contain about 4%

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...

, as well as related compounds including

theobromine Theobromine, also known as xantheose, is the principal alkaloid of '' Theobroma cacao'' (cacao plant). Theobromine is slightly water-soluble (330 mg/L) with a bitter taste. In industry, theobromine is used as an additive and precursor to ...

. 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.'' It contains about three billion base pairs, which was larger than most plants previously sequenced.

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 A hardiness zone is a geographic area defined as having a certain average annual minimum temperature, a factor relevant to the survival of many plants. In some systems other statistics are included in the calculations. The original and most wide ...

s 7 – 9. However, the clonal one is commercially cultivated from the equator to as far north as

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

and

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

on the UK mainland. Many high quality teas are grown at high elevations, up to , as the plants grow more slowly and acquire more flavor. 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.

Chinese teas

The Chinese plant is a small-leafed bush with multiple stems that reaches a height of some . 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, but it was later identified as a variety of ''C. sinensis''. This variety is commonly called Waldenae Camellia. It is seen on Sunset Peak and

Tai Mo Shan Tai Mo Shan is the highest mountain, peak in Hong Kong, with an elevation of . It is located at approximately the geographical centre of the New Territories. The Tai Mo Shan Country Park covers an area of around Tai Mo Shan. It is located ...

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...

. It is also distributed in the

Guangxi Guangxi (; ; Chinese postal romanization, alternately romanized as Kwanghsi; ; za, Gvangjsih, italics=yes), officially the Guangxi Zhuang Autonomous Region (GZAR), is an Autonomous regions of China, autonomous region of the People's Republic ...

province.

Indian teas

Three main kinds of tea are produced in India: *

Assam Assam (; ) is a state in northeastern India, south of the eastern Himalayas along the Brahmaputra and Barak River valleys. Assam covers an area of . The state is bordered by Bhutan and Arunachal Pradesh to the north; Nagaland and Manipur ...

, from the var. ''assamica'' plant, comes from the near sea-level heavily forested northeastern section of India, the state of

. Tea from here is rich and full-bodied. The first tea estates of India was established in Assam in 1837. Teas are manufactured in either the ''orthodox'' process or the ''CTC'' process. *

Darjeeling Darjeeling (, , ) is a town and municipality in the northernmost region of the Indian state of West Bengal. Located in the Eastern Himalayas, it has an average elevation of . To the west of Darjeeling lies the easternmost province of Nepal, ...

, from the var. ''sinensis'' plant, is from the cool and wet

highland region, tucked in the foothills of the

Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

. Tea plantations could be at altitudes as high as . 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 is from a southern region of India almost as high as Darjeeling. Grown at elevations between 1,000 and 2,500 m, Nilgiri teas are subtle and rather gentle, and are frequently blended with other, more robust teas. Camellia sinensis-fruto

Pests and diseases

Tea leaves are eaten by some

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

s, such as the

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...

s of the willow beauty (''Peribatodes rhomboidaria''), a

geometer moth The geometer moths are moths belonging to the family Geometridae of the insect order Lepidoptera, the moths and butterflies. Their scientific name derives from the Ancient Greek ''geo'' γεω (derivative form of or "the earth"), and ''metr ...

Health effects

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. In

clinical research Clinical research is a branch of healthcare science that determines the safety and effectiveness ( efficacy) of medications, devices, diagnostic products and treatment regimens intended for human use. These may be used for prevention, treatm ...

over the early 21st century, tea has been studied extensively for its potential to lower the risk of

human diseases Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, an ...

, but none of this research is conclusive as of 2017.

Biosynthesis of caffeine

Caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...

, a molecule produced in ''C. sinensis'', functions as a

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norm ...

and acts as a natural

pesticide Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...

: it can paralyze and kill herbivorous insects feeding on the plant. Caffeine is a purine alkaloid and its biosynthesis occurs in young tea leaves and is regulated by several enzymes. The biosynthetic pathway in ''C. sinensis'' differs from other caffeine-producing plants such as

coffee Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulant, stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world. S ...

guayusa ''Ilex guayusa'' ( or ) is a species of tree of the holly genus, native to the Amazon Rainforest. One of four known caffeinated holly trees, the leaves of the guayusa tree are harvested fresh and brewed like a tea for their stimulative effects. ...

. Analysis of the pathway was carried out by harvesting young leaves and using reverse transcription PCR to analyze the genes encoding the major enzymes involved in synthesizing caffeine. The gene ''TCS1'' encodes caffeine synthase. Younger leaves feature high concentrations of TCS1 transcripts, allowing more caffeine to be synthesized during this time. Dephosphorylation of xanthosine-5'-monophosphate into

xanthosine Xanthosine is a nucleoside derived from xanthine and ribose. It is the biosynthetic precursor to 7-methylxanthosine by the action of 7-methylxanthosine synthase. 7-Methylxanthosine in turn is the precursor to theobromine (active alkaloid in cho ...

is the committed step for the xanthosines entering the beginning of the most common pathway. A sequence of reactions turns

(9β--ribofuranosylxanthine) into 7-methylxanthosine, then 7-methylxanthine, then

(3,7-dimethylxanthine), and finally into caffeine (1,3,7-trimethylxanthine). Caffeine synthesis in c

Primary green tea catechins

File:(+)-Gallocatechin.svg, (–)-

Epigallocatechin Gallocatechol or gallocatechin (GC) is a flavan-3-ol, a type of chemical compound including catechin, with the gallate residue being in an isomeric trans position. This compound possesses two epimers. The most common, (+)-gallocatechin (GC), CAS ...

File:Epigallocatechin gallate structure.svg, (–)-

Epigallocatechin gallate Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin. EGCG – the most abundant catechin in tea – is a polyphenol under basic research for its ...

File:Epicatechin gallate.svg, (–)-

Epicatechin gallate Epicatechin gallate (ECG) is a flavan-3-ol, a type of flavonoid, present in green tea. It is also reported in buckwheat and in grape. The tea component epicatechin gallate is being researched because in vitro experiments showed it can reverse ...

File:(–)-Epicatechin.svg, (–)-

Epicatechin Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic ...

References

External links

* *
Camellia sinensis
' from

Purdue University Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money ...

The International Camellia Society
* Plant Cultures

Jac.OxfordJournals.org
The effect of a component of tea (''Camellia sinensis'') on methicillin resistance in ''Staphylococcus''.
Suns.Ars-Grin.gov
List of Chemicals in ''Camellia sinensis'' (Dr. Duke's Databases) {{Authority control Medicinal plants Medicinal plants of Asia Tea sinensis Plants used in traditional Chinese medicine Caffeine Plants described in 1753 Taxa named by Carl Linnaeus Flora of Assam