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).
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 white being the least.[4] Kukicha (twig tea) is also harvested from C. sinensis, but uses twigs and stems rather than leaves.
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
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)
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]
