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Camellia sinensis

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Tea Plant
Camellia sinensis foliage
Scientific classification
Kingdom:
Plantae
(unranked):
Angiosperms
(unranked):
Eudicots
(unranked):
Asterids
Order:
Ericales
Family:
Theaceae
Genus:
Camellia
Species:
C. sinensis
Binomial name
Camellia sinensis

Camellia sinensis, the tea plant, is the species of plant whose leaves and leaf buds are used to produce tea. It is of the genus Camellia (Chinese: 茶花; pinyin: Cháhuā), a genus of flowering plants in the family Theaceae. White tea, green tea, oolong, pu-erh tea 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.

There are two major varieties that characterize this species (1) Camellia sinensis var. sinensis (L.) Kuntz and (2) Camellia sinensis var. assamica (Masters) Kitam.[1]

Nomenclature and taxonomy of the variety and its cultivars

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, Carl 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.

List of the Cultivars


Description

Camellia sinensis is native to mainland South and Southeast Asia, but it 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.

Camellia sinensis plant, with cross-section of the flower (lower left) and seeds (lower right).

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

Cultivation

Main article: Tea cultivation

Camellia sinensis is mainly cultivated in tropical and sub-tropical climates, in areas with at least 50 inches of rainfall a year. However, it is commercially cultivated from the equator to as far north as Cornwall on the UK mainland[5]. Many high quality teas are grown at high elevations, up to 1500 meters (5,000 ft), as the plants grow more slowly and acquire a better 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. sinensis sinensis) and the large-leaved Assamese plant (C. sinensis assamica), used mainly for black tea.

Indian Teas

Indian teas are generally classified by the region they are grown in; the three main tea-producing regions in India are Darjeeling, Assam and Nilgiri.

Because of the exquisite growing conditions Darjeeling tea is considered by tea lovers to be the finest of the Indian teas. Unlike almost all other Indian teas Darjeeling uses the Chinese variety (C. sinensis sinensis), which was brought to India in the 19th century by British planters.

Assam is the largest producing area in India, at 473,000 metric tons annually. Assam has 271,768 hectares of tea gardens with 43,293 estates producing tea. The tea uses the Assam type plant native to Assam that the British planters began exploiting commercially in the 19th century. Assam tea has a rich taste (often described as 'malty')[1] and is frequently used as the basis for "breakfast" tea blends.

Nilgiri tea is grown in the South Indian Blue Mountain range. This growing region covers 62,039 hectares and has 62,145 tea estates. Annual tea production is approximately 120,000 tons.

Seed bearing fruit of Camellia sinensis

Chinese Teas

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,[6] but it was later identified as a variety of C. sinensis[7]. 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 Guangxi Province, China.[6]

Diseases

Main article: List of tea diseases

Medical uses

Tea extracts have become field of interest, due to their notional antibacterial activity. Especially the preservation of processed organic food and the treatment of persistent 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

Notes & References

  1. ^ ITIS Standard Report Page Camellia Sinensis retrieved 2009-03-28.
  2. ^ a b Food and Agriculture Organization. "Identification of Japanese tea (Camellia sinensis) cultivars using SSR marker". Retrieved 5 June. {{cite web}}: Check date values in: |accessdate= (help); Cite has empty unknown parameter: |coauthors= (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help)
  3. ^ a b c d e Food and Agriculture Organization. "Varietal differences in the adaptability of tea [Camellia sinensis] cultivars to light nitrogen application". Retrieved 5 June. {{cite web}}: Check date values in: |accessdate= (help); Cite has empty unknown parameter: |coauthors= (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help)
  4. ^ "Camellia sinensis". Retrieved 2008-02-18.
  5. ^ Telegraph Online, 17 Sept 2005. http://www.telegraph.co.uk/gardening/main.jhtml?xml=/gardening/2005/09/17/gtea17.xml
  6. ^ a b The International Camellia Society (ICS)
  7. ^ Ming, T. L. (1992) A revision of Camellia sect. Thea. Acta Botanica Yunnanica. 14(2), 115-132. In Chinese.
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