Gravel root is a perennial member of the aster and daisy family that thrives in the moist woodlands of eastern and central North America. The large pink-to-purple blooms are eye-catching and sweetly-scented, which makes the herb and important food source for butterflies. It is the root, however, for which the plant is harvested.
Because Native Americans had specific uses for gravel root, the plant is known by several common names including Kidney Root and Purple Boneset. The astringent properties of the root are owing to various volatile oils, tannins and an oleoresin called euparin.