Camellia sinensis

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Camellia sinensis is the tea plant, the plant species whose leaves and leaf buds are used to produce tea. White tea, green tea, oolong and black tea are all harvested from this species, but are processed differently to attain different levels of oxidation. Kukicha (twig tea) is also harvested from camellia sinensis, but uses twigs and stems rather than leaves.

The name sinensis means Chinese in Latin. Camellia is taken from the Latinized name of Rev. Georg Kamel, S.J. (1661-1706), a Czech-born Jesuit priest who became both a prominent botanist and a missionary to the Philippines (it is not uncommon for members of the Catholic Jesuit order to combine careers in scholarship with their religious work). Though Kamel did not discover or name the plant, Karl von Linnaeus, the creator of the system of taxonomy still used today, chose his name for the genus of this tree to honor kamel's contributions to science. Older names for the tea plant include Thea bohea, Thea sinensis and Thea viridis.

Camellia sinensis is native to mainland South and Southeast Asia, but is today cultivated across the world, in tropical and subtropical regions. It is an evergreen shrub or small tree that is usually trimmed to below two metres (six feet) when cultivated for its leaves. It has a strong taproot. The flowers are yellow-white, 2.5–4 cm in diameter, with 7 to 8 petals.

The seeds of Camellia sinensis and Camellia 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 cosmetical purposes and originates from the leaves of a different plant.

The leaves are 4–15 cm long and 2–5 cm broad. Fresh leaves contain about 4% caffeine. 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.

The three basic types of tea are green, oolong and black. All use the same leaves of the same plant. Green tea is steamed very soon after picking to stop the oxidation process. Oolong tea is left to oxidize a bit longer and is the type used by most Chinese restaurants. Black tea is oxidized for the longest period of time which produces the darkest of the teas. White tea, a delicacy in the orient now beginning to be found in Western shops, is made from "tea needles," the newest, still folded shoots of leaves at the end of branches. Further distinctions are made to denote the size of the leaves used (the youngest, smallest leaves are generally held to have the highest quality flavor), and the region of origin (in much the same way wine is classified).

Cultivation

Main article: Tea cultivation.

Varieties

Several varieties of C. sinensis are used for tea production:

Assamese variety

The most volume comes from the Assam variety (sometimes called C. sinensis var. assamica or C. assamica), predominantly grown in the Assam region. It is a small tree (single stemmed) with large leaves. In the wild it reaches a height of 6 to 20 meters (20–65 feet) and is native to north-east India, Myanmar, Vietnam, and south China. In tea estates it is kept trimmed to just above waist level. A lowland plant, it requires a high rainfall but good drainage. It does not tolerate extreme temperatures. Discovered in 1823 (though used earlier by local people in their brews), it is one of the two original tea plants. All Assam teas and most Ceylon teas are from this plant. The Assam plant produces malty, earthy drinks, unlike the generally flowery yield of the China plant.

Chinese variety

The Chinese plant (sometimes called C. sinensis var. sinensis) is a small-leaved bush with multiple stems that reaches a height of some 3 meters. It is native to south-east China. The first tea plant to be discovered, recorded and used to produce tea three thousand years ago, it yields some of the most popular teas.

C. sinensis var. waldenae was considered a different species, Camellia waldenae by S.Y.Hu, but it was later identified as a variety of C. sinensis. This variety is commonly called Walden's Camellia. It is seen on Sunset Peak and Tai Mo Shan in Hong Kong. It is also distributed in Giangxi Province, China.

Cambodian variety

The Cambodian plant is sometimes called C. sinensis var. parvifolia. Its leaves are in size between the Assam and Chinese varieties; it is a small tree with several stems. It is sometimes referred to as a hybrid of the Assam and China plants.

Diseases

Medical uses

• The leaves have been used in traditional Chinese medicine (TCM), and other medical systems to treat asthma, bronchodilator, angina pectoris, peripheral vascular disease, and coronary artery disease.

Tea extracts have become field of interest, due to their notional antibacterial activity. Especially the preservation of processed organic food and the treatment of persistant bacterial infections are being investigated.

• Green tea leaves and extracts have shown to be effective against bacteria responsible for bad breath.
• The tea component epicatechin gallate is being researched because in-vitro experiments showed that it can reverse methicillin resistance in bacteria like Staphylococcus aureus. If confirmed, this means that the combined intake of a tea extract containing this component will enhance the effectiveness of methicillin treatment against some resistant bacteria.

See also

• Barry's Tea
• Anna Russell, Duchess of Bedford
• Assam tea
• Bubble tea
• Capputeano
• Ceylon tea (disambiguation)
• Chinese tea culture
• Chinese herbology
• Darjeeling tea
• Earl Grey, a blend of tea made with bergamot orange.
• English Breakfast tea
• Flowering tea, a type of tea that opens up when steeped
• Frederick John Horniman
• Gunpowder tea
• The health benefits of tea
• Iced tea
• Irish Breakfast tea
• ISO 3103, a method of brewing tea according to the ISO.
• Japanese tea ceremony
• Kaempferol a flavanoid found in green and black teas and associated with reduced risk of heart disease
• Korean tea ceremony
• Lapsang souchong

• Lipton
• List of tea companies
• Masala chai
• Mate
• Orange Pekoe
• Peppermint tea
• Prince of Wales tea blend
• Rooibos
• Samovar
• Snapple
• Tasseography, a method of divination by reading tea leaves.
• Tazo
• Tea
• Tea Classics
• Tea tree is a name sometimes applied to a number of different plants unrelated to the tea plant.
• Tea tree oil is derived from Melaleuca alternifolia which is native to Australia and unrelated to the tea plant discussed here.
• Thai tea
• Turkish tea
• Yorkshire Tea

References

External links

• Camellia sinensis from Purdue University
• Plant Cultures: botany and history of the tea plant
• Camellia sinensis Classification from Toklai Tea Research Station, Jorhat, Assam.
• Antibacterial Activity of Green Tea Extracts against Streptococcus anginosus group: http://ci.nii.ac.jp/naid/10017425510/en/
• The effect of a component of tea (Camellia sinensis) on methicillin resistance in Staphylococcus: http://jac.oxfordjournals.org/cgi/content/abstract/42/2/211
• List of Chemicals in Camellia sinensis (Dr. Duke's Databases)

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Last updated on Saturday March 08, 2008 at 10:27:45 PST (GMT -0800)
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