benzoin) leaves used to make a tea by some native peoples of eastern North America Spruce tea, made from needles of spruce trees Staghorn sumac, fruit can be made into a lemonade Stevia, can be used to make herbal tea, or as a sweetener in other beverages St. John's wort Thyme, contains thymol Tulsi, or holy basil Turmeric tea Uncaria tomentosa, commonly known as cat's claw Valerian is used as a sedative. Verbena (vervain) Wax gourd in East Asia and Southeast Asia. Wong Lo Kat, a recipe for herbal tea from Guangdong, China since the Qing Dynasty Woodruff Yarrow Health risks While most herbal teas are safe for regular consumption, some herbs have toxic or allergenic effects. Among the greatest causes of concern are: Comfrey, which contains alkaloids which may be harmful to the liver from chronic use, and particularly is not recommended during pregnancy or when prescription drugs are used; comfrey is not recommended for oral use. Lobelia, which contains alkaloids and has traditional medicine uses for smoking cessation, may cause nausea, vomiting, or dizziness at high doses. Herbal teas can also have different effects from person to person, and this is further compounded by the problem of potential misidentification. The deadly foxglove, for example, can be mistaken for the much more benign (but still relatively toxic to the liver) comfrey. Care must be taken not to use any poisonous plants. The US does not require herbal teas to have any evidence concerning their efficacy, but does treat them technically as food products and require that they be safe for consumption. Fruit or fruit-flavored tea is usually acidic and thus may contribute to erosion of tooth enamel. Contamination Depending on the source of the herbal ingredients, herbal teas, like any crop, may be contaminated with pesticides or heavy metals. According to Naithani & Kakkar (2004), "all herbal preparations should be checked for toxic chemical residues to allay consumer fears of exposure to known neuro-toxicant pesticides and to aid in promoting global acceptance of these products". During pregnancy In addition to the issues mentioned above which are toxic to all people, several medicinal herbs are considered abortifacients, and if consumed by a pregnant individual could cause miscarriage. These include common ingredients like nutmeg, mace, papaya, bitter melon, verbena, saffron, slippery elm, and possibly pomegranate. It also includes more obscure herbs, like mugwort, rue, pennyroyal, wild carrot, blue cohosh, tansy, and