Herbal teas or tisanes are beverages made by infusing plant material (other than that of Camellia sinensis–true tea or Coffea–coffee) in hot water. As indicated by the name, many of the most popular herbal teas are made from culinary herbs like rosemary or medicinal herbs like chamomile. But many “herbal” teas are in fact not made from a herb (the leaves of a plant) but rather are made from spices (the seeds, bark or roots of a plant) like fennel seeds, or plant material that isn’t really a herb or a spice, like rose hip.
In practice, “herbal tea” encompasses all plant infusions that aren’t true tea (including black tea, green tea and oolong) or coffee.