Appearance: Perennial herbaceous plant, 3' tall, up to 5' in shaded areas, and erect. A single stem branches extensively toward the top into short stems forming a flat-topped cluster of numerous button-like flower heads; plants have medicinal properties.
Leaves: Alternate, pinnately compound (leaflets arranged on both sides of a common stalk), irregularly lobed. Leaves become smaller towards the top of the stalk, and are strongly aromatic when crushed.
Flowers: Bright yellow daisy-like discs up to 0.5" wide, lacking rays, blooming from July through October.
Seeds: Numerous tufted seed dispersed by wind and water.
Roots: Spreads vegetatively forming new plants from even small root fragments.
- Video on Common Tansy Identification (University of Wisconsin)
- Minnesota Noxious Weeds Booklet (MN DOT)
- Common Tansy Fact Sheet (Montana State University)
- US Forest Service Fact Sheet
- NRCS Management of Tansy
- Biological Control of Invasive Plants in Minnesota brochure