o   Black tea is a type of tea that is more oxidized than oolong, green and white teas. Black tea is generally stronger in flavor than the less oxidized teas. All four types are made from leaves of the shrub (or small tree) Camellia sinensis. Two principal varieties of the species are used – the small-leaved Chinese variety plant (C. sinensis subsp. sinensis), used for most other types of teas, and the large-leaved Assamese plant (C. sinensis subsp. assamica), which was traditionally mainly used for black tea, although in recent years some green and white have been produced.

In the year of 1900 , Consul General of Iran in India , Mr. Mohammad Mirza –ye- Chaikar known as Kashefolsaltaneh or Tea Father of Iran, importing 1000 tea plants from India to Iran and because the climate of North of Iran is as like as India, planted them there. Little by little more farmers got interested to tea and start to plant tea in Iran north area. Iran north area is in the same level of the sea and very humid, raining and green, so, it is a very good place to cultivate tea. In Iran also they call it Chai". So, when you go to coffee shop, you can ask for Chai.