Common Tansy (Tanacetum vulgare)

Gallery:

Common names:

common tansy

Scientific Name:

Tanacetum vulgare (syns. Chrysanthemum vulgare, Tanacetum boreale)

Description:

Common tansy is an aromatic perennial with rhizomes, reaching 1 to 5 feet tall, with fern like foliage and yellow button-like flowers. Flowerheads are numerous, button-like and yellow. They are 1/4 to 1/2 inches across in flat-topped dense clusters. Flowerheads composed of all disk flowers and are absent of ray flowers. Leaves are alternate and pinnately compound (leaflets arranged on both sides of a common stalk). They are deeply divided into numerous, narrow, toothed segments. Leaves become smaller towards the top of the stalk and are strongly aromatic when crushed.

Life cycle:

Perennial

Height of mature plants

1-5 feet

Flower color:

Yellow

Bloom time:

June through August

Look-a-likes:

Common St. Johnswort (Hypericum perforatum) and tansy ragwort (Senecio jacobaea) may be mistaken for common tansy. Common St. Johnswort flowers have 5 petals per flower while common tansy does not have any petals (ray flowers) and and tansy ragwort has on average of 13 ‘petals’ (ray flowers).

Habitat:

The areas most infested by Weed X are important places that people care about.  Weed X especially loves those particular places that are liked by all of these really cool native plants.  So watch for Weed X is these really specific important places.

Impacts:

Common tansy is reported to be poisonous to livestock, though it is seldom grazed due to its strong odor. It displaces forage plants, reduces wildlife habitat and species diversity.

Noxious Weed Listing:

Origin:

Asia and Europe

Links:

Washington Noxious Weed Profile
Invasive.org profile
CABI Invasive Species Compendium

 

Do NOT follow this link or you will be banned from the site!