The Botany of the Tea Plant

Every tea comes from the same plant: the tea plant (Camellia sinensis), an evergreen woody member of the Theaceae family. In the wild it can grow into a tree over ten metres tall; in a garden it is pruned to a waist-high bush. Its most important “alter egos” are two varieties with very different leaf sizes — which decide, from the source, what a leaf is best made into.

The China type (var. sinensis) is lower in polyphenols and hardier, suited to green, oolong and white tea; the Assam type (var. assamica) has large leaves, high polyphenols and loves heat, suited to black tea and pu-erh. This is why Jiangnan makes delicate greens while Assam and Yunnan make bold black tea and pu-erh.

Classification and name

The tea plant belongs to the family Theaceae, genus Camellia, with the botanical name Camellia sinensis (L.) Kuntze — a close relative of the ornamental camellia. Being evergreen, it carries leaves year-round, the basis for multiple harvests.

Morphology

A wild tea plant can become a tree over ten metres tall (Yunnan still has ancient trees centuries to over a thousand years old); in gardens it is repeatedly pruned into a 1–2 m bush, both for easy plucking and to push new shoots.

• Leaves: alternate, leathery and glossy, with serrated margins. A diagnostic feature is the looped (closed) venation — side veins curve up to join the vein above instead of reaching the margin.
• Trichomes: young buds and leaves have fine silvery hairs (trichomes) underneath — the “white down” tied to the downy aroma and look of teas like Silver Needle.
• Flowers and fruit: in autumn–winter it bears fragrant white flowers with yellow stamens, about 2–4 cm across, solitary or in pairs; the fruit is a capsule with 1–3 oil-rich seeds.

The two varieties

The comparison above shows the core differences. The key point: variety is the “base coat” of the raw material — it genetically sets leaf size, compounds (especially polyphenols) and hardiness, on top of which terroir and craft build the finished tea. Many intermediate and hybrid types exist between the two.

Propagation and cultivars

Tea can be grown from seed (sexual lines, “population” stock, with much variation) or from cuttings (clonal “cultivars” such as Fuding Da Bai, Longjing 43, Tieguanyin). Modern quality teas mostly use clonal cultivars for consistency.

Growing conditions

Tea likes warm, humid conditions and well-drained acidic soil (about pH 4.5–6), needs ample even rainfall, dislikes waterlogging and hard frost, and tolerates some shade. High altitude, cloud and large day–night temperature swings tend to let leaves accumulate more compounds and develop better flavour.

See also

• The Flavour Chemistry of the Fresh Leaf — what’s in the leaf and how it shapes taste
• The World Tea Map — how terroir and cultivar together shape the leaf

References

1. Camellia Sinensis Varieties and Cultivars. Anshim Tea. https://anshimtea.com/article/camellia-sinensis-varieties-and-cultivars
2. Camellia sinensis — overview. ScienceDirect Topics. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/camellia-sinensis