Common tansy (Tanacetum vulgare)

Description:

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.

Ecological Threat:

Common tansy is wide spread across most northern United States and Canadian provinces.
It is still cultivated in gardens and is common along roadsides and abandoned farmyards in northern Minnesota and along the north shore of Lake Superior. South sloping open areas are most vulnerable.
It was introduced to the United States from Europe for medicinal and horticultural purposes.
Common tansy is on the MDA Secondary noxious weeds list in Minnesota.

Control Methods:

Grazing

Tansy is distasteful and even toxic to some grazing animals, however, one source claims that sheep graze it and are not affected

Chemical

Spot-spraying with selective broadleaf herbicide such as clopyralid, metsulfuron or 2,4-D

Invasive species

Nature

Common tansy (Tanacetum vulgare)

Description:

Ecological Threat:

Control Methods: