From the most tea-producing region in the most tea-producing country in the world comes Assam tea, a sultry, malty black tea among India's most famous. Discovered in the early 1800s growing wild in the tropically warm and wet Assam region at the edge of the eastern Himalayan mountains, this indigenous tea is versatile enough to have been planted throughout Asia, proving extremely prolific, easy to grow, and able to be harvested frequently.
'Assam' on Serious Eats
What we call "black tea" is known in much of Asia as "red tea"—referring more to the color in the cup than the blackened appearance of the fully oxidized leaves before brewing. It may also be useful to distinguish between the origins of black teas, such as Chinese (whose leaves are picked earlier and withstand more oxidation) and black teas of other origins, e.g. Africa, India and Sri Lanka (whose leaves are picked later and are less oxidized). The difference in processing methods of these teas is reflected in their flavor, and affects the way in which you may choose to brew them.