All classes of tea come from the same plant (camellia sinensis). The different classes of tea (e.g. Black tea, Green tea, Oolong tea) are the result of differences in the tea manufacturing process, and not due to different types of tea plants. However, from experience, tea manufacturers have discovered that certain varieties, locations, and seasons tend to produce Camellia Sinesis (tea plants), which produce better qualities of certain classes of tea.