Camellia sinensis

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Camellia sinensis
Csinensis.jpg
Tea Bud.jpg
Camellia sinensis foliage
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Ericales
Family: Theaceae
Genus: Camellia
Species:
C. sinensis
Binomial name
Camellia sinensis
Tea plants native range.jpg
Native range of Camellia sinensis
Synonyms [2]
Camellia sinensis
    • Camellia angustifoliaHung T. Chang
    • Camellia arborescensHung T. Chang & F. L. Yu
    • Camellia assamica(J. W. Masters) Hung T. Chang
    • Camellia dehungensisHung T. Chang & B. H. Chen
    • Camellia dishiensisF. C. Zhang et al.
    • Camellia longlingensisF. C. Zhang et al.
    • Camellia multisepalaHung T. Chang & Y. J. Tang
    • Camellia oleosa(Loureiro) Rehder
    • Camellia parvisepalaHung T. Chang.
    • Camellia parvisepaloidesHung T. Chang & H. S. Wang.
    • Camellia polyneuraHung T.Chang, Y.J.Tan & P.S.Wang
    • Camellia theaLink
    • Camellia theiferaGriffith
    • Camellia waldeniaeS. Y. Hu
    • Thea assamicaJ. W. Masters
    • Thea boheaL.
    • Thea cantonensisLoureiro
    • Thea chinensisSims
    • Thea cochinchinensisLoureiro
    • Thea grandifoliaSalisbury
    • Thea oleariaLoureiro ex Gomes
    • Thea oleosaLoureiro
    • Thea parvifoliaSalisb.
    • Thea sinensisL.
    • Thea viridisL.
    • Theaphylla cantonensis(Loureiro) Rafinesque

Camellia sinensis is a species of evergreen shrub or small tree in the flowering plant family Theaceae. Its leaves, leaf buds, and stems can be used to produce tea. Common names include tea plant, tea shrub, and tea tree (unrelated to Melaleuca alternifolia , the source of tea tree oil, or the genus Leptospermum commonly called tea tree).

Contents

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, [3] but are processed differently to attain varying levels of oxidation with black tea being the most oxidized and green being the least. [4] Kukicha (twig tea) is also harvested from C. sinensis, but uses twigs and stems rather than leaves.

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 2 m (6.6 ft) when cultivated for its leaves. It has a strong taproot. The flowers are yellow-white, 2.5–4 cm (0.98–1.57 in) in diameter, with seven or eight petals.

Flower of tea plant Flower of Tea plant.jpg
Flower of tea plant
Pollen grains of C. sinensis Pollen grains of a Tea plant.jpg
Pollen grains of C. sinensis

The seeds of C. sinensis and 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.

C. sinensis plant, with cross-section of the flower (lower left) and seeds (lower right) Camellia sinensis - Kohler-s Medizinal-Pflanzen-025.jpg
C. sinensis plant, with cross-section of the flower (lower left) and seeds (lower right)
C. sinensis Camellia sinensis MHNT.BOT.2016.12.24.jpg
C. sinensis

The leaves are 4–15 cm (1.6–5.9 in) long and 2–5 cm (0.79–1.97 in) broad. Fresh leaves contain about 4% caffeine, as well as related compounds including theobromine. [5] The young, light-green leaves are preferably harvested for tea production when 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. [6] It contains about three billion base pairs, which was larger than most plants previously sequenced. [7]

Taxonomy

The generic name Camellia is taken from the Latinized name of Rev. Georg Kamel, [8] SJ (1661–1706), a Moravian-born Jesuit lay brother, pharmacist, and missionary to the Philippines.

Carl Linnaeus chose his name in 1753 for the genus to honor Kamel's contributions to botany [9] (although Kamel did not discover or name this plant, or any Camellia, [10] and Linnaeus did not consider this plant a Camellia but a Thea). [11]

Robert Sweet shifted all formerly Thea species to the genus Camellia in 1818. [12] The name sinensis means "from China" in Latin.

Four varieties of C. sinensis are recognized. [2] 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. [2] 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. [13]

Tea plants are native to East Asia, and probably originated in the borderlands of north Burma and southwestern China. [14]

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. [15] [16]

Given their genetic differences forming distinct clades, 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). 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 haplotypes 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. [15] [16]

Assuming a generation of 12 years, Chinese small leaf tea is estimated to have diverged from Assam tea around 22,000 years ago; this divergence would correspond to the last glacial maximum, [15] [16] while Chinese Assam tea and Indian Assam tea diverged 2,800 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. [17]

Cultivars

Hundreds, [18] if not thousands of cultivars of C. sinensis are known. Some Japanese cultivars include:

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 zones 7–9. However, the clonal one is commercially cultivated from the equator to as far north as Cornwall and Scotland on the UK mainland. [21] [22] Many high quality teas are grown at high elevations, up to 2,200 m (7,200 ft), 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 3 m (9.8 ft). 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, [23] but it was later identified as a variety of C. sinensis. [24] This variety is commonly called Waldenae Camellia. It is seen on Sunset Peak and Tai Mo Shan in Hong Kong. It is also distributed in the Guangxi province. [23]

Indian teas

Three main kinds of tea are produced in India:

Seed-bearing fruit of C. sinensis Camellia sinensis-fruto.jpg
Seed-bearing fruit of C. sinensis

Pests and diseases

Tea leaves are eaten by some herbivores, such as the caterpillars of the willow beauty (Peribatodes rhomboidaria), a geometer moth.

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. [25] [26] 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. [25]

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. [27] Caffeine is a purine alkaloid and its biosynthesis occurs in young tea leaves and is regulated by several enzymes. [28] [29] The biosynthetic pathway in C. sinensis is similar to other caffeine-producing plants such as coffee or guayusa. [30] 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 is the committed step for the xanthosines entering the beginning of the most common pathway. A sequence of reactions turns xanthosine (9β-D-ribofuranosylxanthine) into 7-methylxanthosine, then 7-methylxanthine, then theobromine (3,7-dimethylxanthine), and finally into caffeine (1,3,7-trimethylxanthine).

Biochemical pathway detailing caffeine synthesis in C. sinensis Caffeine synthesis in c. sinensis.png
Biochemical pathway detailing caffeine synthesis in C. sinensis

See also

Primary green tea catechins

Related Research Articles

<span class="mw-page-title-main">Oolong</span> Partially oxidized Chinese tea

Oolong (, ; Chinese: 烏龍茶 is a traditional semi-oxidized Chinese tea produced through a process that includes withering the leaves under strong sun and allowing some oxidation to occur before curling and twisting. Most oolong teas, especially those of fine quality, involve unique tea plant cultivars that are exclusively used for particular varieties. The degree of oxidation, which is controlled by the length of time between picking and final drying, can range from 8% to 85% depending on the variety and production style. Oolong is especially popular in southeastern China and among ethnic Chinese in Southeast Asia, as is the Fujian preparation process known as the gongfu tea ceremony.

<span class="mw-page-title-main">Tea</span> Hot drink made from water and tea leaves

Tea, or cha, 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 northern Myanmar. Tea is also made, but rarely, from the leaves of Camellia taliensis. After plain water, tea is the most widely consumed drink in the world. There are many different types of tea; some have a cooling, slightly bitter, and astringent flavour, while others have profiles that include sweet, nutty, floral, or grassy notes. Tea has a stimulating effect in humans, primarily due to its caffeine content.

<span class="mw-page-title-main">Herbal tea</span> Beverage made from infusing or decocting plant material in hot water

Herbal teas, also known as herbal infusions and less commonly called tisanes, are beverages made from the infusion or decoction of herbs, spices, or other plant material in hot water; they do not usually contain any true tea. Often herb tea, or the plain term tea, is used as a reference to all sorts of herbal teas. Many herbs used in teas/tisanes are also used in herbal medicine. Some herbal blends contain true tea.

<i>Camellia</i> Genus of flowering plants in the tea family Theaceae

Camellia is a genus of flowering plants in the family Theaceae. They are found in tropical and subtropical areas in eastern and southern Asia, from the Himalayas east to Japan and Indonesia. There are more than 220 described species. Camellias are popular ornamental, tea and woody-oil plants that have been cultivated throughout the world for centuries. To date, over 26,000 cultivars, with more than 51,000 cultivar names including synonyms, have been registered or published.

<span class="mw-page-title-main">Pu'er tea</span> Variety of fermented tea produced in the Yunnan province of China

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, and is typically applied after the tea leaves have been sufficiently dried and rolled. As the tea undergoes controlled microbial fermentation, it also continues to oxidize, which is also controlled, until the desired flavors are reached. This process produces tea known as hēichá (黑茶), literally "black tea", though the term is commonly translated to English as "dark tea" to distinguish it from the English-language black tea.

<span class="mw-page-title-main">White tea</span> Tea from the Camellia sinensis plant

White tea may refer to one of several styles of tea which generally feature young or minimally processed leaves of the Camellia sinensis plant.

<span class="mw-page-title-main">Theaceae</span> Family of flowering plants

Theaceae, the tea family, is a 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 genera, depending on the source and the method of circumscription used. The family Ternstroemiaceae has been included within Theaceae; however, the APG III system of 2009 places it instead in Pentaphylacaceae. Most but not all species are native to China and East Asia.

<span class="mw-page-title-main">Assam tea</span> Black tea

Assam tea is a black tea named after Assam, India, the region of its production. It is manufactured specifically from the plant Camellia sinensis var. assamica (Masters). The Assam tea plant is indigenous to Assam—initial efforts to plant the Chinese varieties in Assam soil did not succeed. Assam tea is now mostly grown at or near sea level and is known for its body, briskness, malty flavour, and strong, bright colour. Assam teas, or blends containing Assam tea, are often sold as "breakfast" teas. For instance, Irish breakfast tea, a maltier and stronger breakfast tea, consists of small-sized Assam tea leaves.

<span class="mw-page-title-main">Nilgiri tea</span> Black tea from Nilgiris district in Tamil Nadu, India

Nilgiri tea is a drink made by infusing leaves of Camellia sinensis that is grown and processed in the Nilgiris district in Tamil Nadu, India. The leaves are processed as black tea, though some estates have expanded their product offerings to include leaves suitable for making green, white and oolong teas. It is generally described as being a brisk, fragrant and full-bodied tea. The region produces both rolled and crush, tear, curl tea and it is predominantly used for blending. Nilgiri tea is also used for making iced tea and instant tea.

<span class="mw-page-title-main">History of tea</span>

The history of tea spreads across multiple cultures over the span of thousands of years. With the tea plant Camellia sinensis native to East Asia and probably originating in the borderlands of southwestern China and northern Myanmar. One of the earliest accounts of tea drinking is dated back to China's Shang dynasty, in which tea was consumed as a medicinal drink. An early credible record of tea drinking dates to the 3rd century AD, in a medical text written by Chinese physician Hua Tuo. It first became known to the western world through Portuguese priests and merchants in China during the early 16th century. Drinking tea became popular in Britain during the 17th century. The British introduced commercial tea production to British India, in order to compete with the Chinese monopoly on tea by stealing green tea leaves from China, transporting them by train/road, resulting in them being fermented and thought fermented tea is the tea drunk in China. Hence the tea drank in the West is mostly fermented and not green fresh tea.

<i>Camellia japonica</i> Species of flowering plant

Camellia japonica, known as common camellia, or Japanese camellia, is a species of Camellia, a flowering plant genus in the family Theaceae. There are thousands of cultivars of C. japonica in cultivation, with many colors and forms of flowers. Despite its common name, it is native to China, not Japan. The cultivation of Camellia japonica also started in China. Its widespread cultivation can be traced back to the Song Dynasty, when 15 varieties of Camellia japonica were recorded in literature. It was later introduced to Japan. It grows in forests, at altitudes of around 300–1,100 metres (980–3,600 ft).

<span class="mw-page-title-main">Baimudan tea</span> White tea

Bai Mudan is a type of white tea made from plucks each with one leaf shoot and two immediate young leaves of the Camellia sinensis plant. Bai Mudan is sometimes preferred by white tea drinkers for its fuller flavor and greater potency than the other major type of white tea, Bai Hao Yinzhen. The latter is made purely with leaf shoots, and so it is comparatively softer and more subtle. The typical taste of Bai Mudan is a result of both the processing and the tea plant cultivars employed in the production.

<span class="mw-page-title-main">Nepali tea</span>

Nepali tea is a beverage made from the leaves of tea plants grown in Nepal. They are distinctive in appearance, aroma and taste, but are similar in many ways to tea produced in Darjeeling tea, perhaps because the eastern zones of Nepal have geography and topography similar to Darjeeling. Its relatively smaller production quantities mean that teas from Nepal are less well known than those from Darjeeling.

<span class="mw-page-title-main">Darjeeling tea</span> Type of black tea from India

Darjeeling tea is a tea made from Camellia sinensis var. sinensis that is grown and processed in Darjeeling district or Kalimpong district in West Bengal, India. Since 2004, the term Darjeeling tea has been a registered geographical indication referring to products produced on certain estates within Darjeeling and Kalimpong. The tea leaves are processed as black tea, though some estates have expanded their product offerings to include leaves suitable for making green, white, and oolong teas.

<span class="mw-page-title-main">Tea seed oil</span> Oil obtained from the tea plant

Tea seed oil is an edible plant oil. It is obtained from the seeds of Camellia oleifera.

<span class="mw-page-title-main">Indian tea culture</span> Culture in India

India is the second largest producer of tea in the world after China, including the famous Assam tea and Darjeeling tea. Tea is the 'State Drink' of Assam. Following this the former Planning Commission Deputy Chairman, Montek Singh Ahluwalia had plans to officially recognise tea as the Indian "National Drink" in 2013. According to the ASSOCHAM report released in December 2011, India is the world's largest consumer of tea, consuming nearly 30% of global output. India is also the second-largest exporter of tea, after China.

<span class="mw-page-title-main">Taiwanese tea</span> Teas from Taiwan

Taiwanese tea includes four main types: oolong tea, black tea, green tea and white tea. The earliest record of tea trees found in Taiwan is from 1717 in Shui Sha Lian (水沙連), present-day Yuchi and Puli, Nantou County. Some of the teas retain the island country's former name, Formosa.

<i>Andraca bipunctata</i> Species of moth

Andraca bipunctata is a moth of the family Endromidae. It is found in China (Yunnan), India, Bhutan, northern Thailand, Myanmar and Nepal. The larvae are referred to as bunch caterpillars.

<span class="mw-page-title-main">Black tea</span> Type of tea

Black tea 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 leaves of the shrub Camellia sinensis, though Camellia taliensis is also used rarely.

<i>Camellia taliensis</i> Species of flowering plant

Camellia taliensis is a small species of evergreen shrub whose leaves and leaf buds are used to produce tea.

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