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
Darjeeling tea 1839 from Kathmandu, Nepal. In 1841, he brought seeds of the Chinese tea plant ("Camellia sinensis") from Kumaun and began to experiment with tea planting in Darjeeling. The British government also established tea nurseries during that period (1847). Commercial development began during the 1850s. In 1856, the Alubari tea garden was opened by the Kurseong and Darjeeling Tea company, followed by others. According to the Tea Board of India, "Darjeeling Tea" can only refer to tea that has been cultivated, grown, produced, manufactured and processed in tea gardens (see 'Tea Estates' section below) in the hilly areas of Sadar Subdivision,