Black tea is a "true" tea (i.e. Camellia sinensis) made from leaves more heavily oxidized than the white, green, and oolong varieties. Black tea is generally stronger in flavor and contains more caffeine than the more lightly oxidized teas. Generally, unblended black teas are named after the region in which they are produced. Often, different regions are known for producing teas with characteristic flavors. Black tea accounts for over ninety percent of all tea sold in the West.