Herbal tea is made up of herbs, spices, or other plant material, and typically does not have caffiene. Herbal teas differ from true teas, by not using processed leaves from the tea plant. As such, herbal teas are commonly classified as infusion or tisane. Herbal teas can be composed of fresh or dried flowers, seed, leaves or roots. In general, they are prepared by pouring boiling water over the mixture and left to steep for several minutes. Seeds and roots can also be boiled on a stove, strained, and sweetened to taste.