Late boneset, also known as late-flowering thoroughwort, is an upright perennial with opposite leaves topped with sprays of small white flowers in August and September. It reaches a height of four to five feet, branching only near the top as the flattened clusters of flowers develop. The stems and cylindrical calyxes are covered with fine down. It is very similar to tall boneset, blooming at the same time, but can be distinguished by narrow leaves that are broader at the base, with a distinct petiole. It grows in open sunny areas and is not fussy about soil conditions. It is a native plant in the aster family, widespread in eastern and central North America, and attracts many pollinators.