Black tea is a variety of tea that is more oxidized than the Oolong, green, and white teas. Black tea is the stronger in flavour and usually contains the most caffeine. Both varieties of the Camellia species are used to make Black tea: Camellia sinensis Sinensis (also used for green and white teas) and the Assamese plant, Camellia sinensis assamica, which has only been used for black tea in the past, but in recent years has been used for Green. In Chinese languages, Black tea is known literally as "crimson tea", a closer description to the colour of the tea produced. The name Black tea could otherwise refer to the colour of the leaves after processing.