Herbal teas are infusions of dried herbs, flowers, fruit or roots, such as peppermint, rooibos, hibiscus or ginger, rather than leaves of the tea plant. Brewed plain, a 240 ml cup has about 2 kcal and practically no nutrients, and most herbal teas are naturally caffeine-free. Yerba mate and guayusa are exceptions: they are brewed like herbal teas but do contain caffeine.