The plant readily invades roadsides, fence rows, pastures, stream banks, and waste areas throughout North America. While it is not a statewide noxious weed, it has been declared noxious in Broadwater, Beaverhead, Gallatin, Silverbow, Meagher, and Carbon counties. Stems grow in large clusters up to 6 feet high and are mostly hairless, often purplish-red in color, and extensively branched towards the top. Leaves are finely divided into leaflets giving the plant a fern-like appearance.
Common tansy has a strong odor when crushed.
Common tansy, native to Europe, has a long history of medicinal use. It was first introduced to North America for use in folk remedies and as an ornamental plants. Use of common tansy led the governor of Massachusetts to list common tansy as a necessary plant for colonial herb gardens in the 1600s. This led to widespread cultivation of the plant and its inevitable escape into fields and roadsides. By the 1800s this weed was growing wild throughout the Northeast.