Linden is a species of deciduous tree that occurs naturally throughout Europe and North America. Although it is sometimes called lime tree, it is no relation to the citrus fruit. In fact, linden is in the Malvaceae family, which includes basswood and mallows.
The flowers and leaves have long been used to make toiletries and cosmetics due to their mucilage and flavonoid content. The herb is also used in teas and to make soothing syrups and lozenges. Although linden is associated with promoting relaxation, it is non-narcotic. However, be aware that this herb may increase the effects of anxiety medications and other prescription drugs.