Herbal teas can be made with fresh or dried flowers, leaves, seeds or roots, generally by pouring boiling water over the plant parts and letting them steep for a few minutes. Seeds and roots can also be boiled on a stove. The tisane is then strained, sweetened if so desired, and served. Many companies produce herbal tea bags for such infusions.
On the other hand, flavoured teas are prepared by adding other plants to an actual tea (black, oolong, green, yellow, or white tea); for example, the popular Earl Grey tea is black tea with bergamot, jasmine tea is Chinese tea with jasmine flowers, and genmaicha is a Japanese green tea with toasted rice.
Source : http://en.wikipedia.org/wiki/Herbal_tea
See Also : Florist, Florists, Flower