Ocimum tenuiflorum, commonly known as holy basil or tulsi, is an aromatic perennial plant in the family Lamiaceae. It is native to tropical and subtropical regions of Australia, Malesia, Asia, and the western Pacific. It is widely cultivated throughout the Southeast Asian tropics. This plant has escaped from cultivation and has naturalized in many tropical regions of the Americas. It is an agricultural and environmental weed.

Herbal teas, also known as herbal infusions and less commonly called tisanes, are beverages made from the infusion or decoction of herbs, spices, or other plant material in hot water; they do not usually contain any true tea. Often herb tea, or the plain term tea, is used as a reference to all sorts of herbal teas. Many herbs used in teas/tisanes are also used in herbal medicine. Some herbal blends contain true tea.