Decaffeination this trait could be bred into other coffee plants by crossing them with "C. charrieriana", or an equivalent effect could be achieved by knocking out the gene for caffeine synthase in normal coffee plants. Tea may also be decaffeinated, usually by using processes analogous to the direct method or the CO process, as described above. The process of oxidizing tea leaves to create black tea ("red" in Chinese tea culture) or oolong tea leaves from green leaves does not affect the amount of caffeine in the tea, though tea-plant subspecies (i.e., "Camellia sinensis sinensis" vs. "Camellia sinensis assamica") may differ
Camellia sinensis 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. The Chinese plant (sometimes called "C. sinensis" var. "sinensis") is a small-leafed bush with multiple stems that reaches a height of some 3 meters. It is native to southeast China. The first tea plant to be discovered, recorded and used to produce tea 3,000 years ago, it yields some of the most