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 Robert Sweet shifted all formerly "Thea" species to the genus "Camellia" in 1818. The name "sinensis" means "from China" in Latin. Four varieties of "Camellia sinensis" are recognized. Of these, "C. sinensis" var. "sinensis" and "C. sinensis" var. "assamica" (JW Masters) Kitamura are most commonly used for tea, and "C. sinensis" var. "pubilimba" Hung T. Chang and "C. sinensis" var. "dehungensis" (Hung T. Chang & BH Chen) TL Ming are sometimes used locally. There are hundreds, if not thousands of cultivars of "C. sinensis." Some Japanese cultivars include: "Camellia sinensis" is native to East Asia, the Indian Subcontinent and Southeast