Flower profile

Common tansy

Tanacetum vulgare

Introduced in the lower 48

Common tansy is a wildflower that USDA PLANTS lists as introduced in the lower 48 states. It's on our flower lists for 11 states, and across the U.S. it's most often seen in bloom in July–October.

45states

11of our state lists

23,898U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Idaho, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, Rhode Island, South Dakota, Washington, Wisconsin

🚫

Regulated invasive plant in Washington, Minnesota, Wisconsin and Montana. It's on those states' official invasive plant lists (Washington: Class B noxious weed (control required in listed regions); Minnesota: Prohibited noxious weed (control); Wisconsin: Restricted invasive species; Montana: Priority 2B noxious weed). Please don't plant or share it there. ^{WAC 16-750 MN noxious weed list NR 40 ARM 4.5.206–210}

Quick look

Tansy is a perennial, herbaceous flowering plant in the genus Tanacetum in the family Asteraceae, native to temperate Europe and Asia. It has been introduced to other parts of the world, including Australia and North and South America, and in some areas has become invasive. It is also known as common tansy, bitter buttons, cow bitter, or golden buttons. The Latin word vulgare means "common".
From Wikipedia's article Tansy, CC BY-SA 4.0.

It belongs to the Asteraceae family. ^iNaturalist
USDA PLANTS describes it as an herb (forb) with a perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as introduced in the lower 48 states and records it in 45 states. ^{USDA PLANTS}
In Washington, most iNaturalist sightings of it in flower come in July–October. ^iNaturalist
In Massachusetts, most iNaturalist sightings of it in flower come in July–October. ^iNaturalist
iNaturalist has 3,639 research-grade sightings of it in Washington, ranking #45 among the 110 flowers on our Washington list. ^iNaturalist
iNaturalist has 3,616 research-grade sightings of it in Massachusetts, ranking #41 among the 110 flowers on our Massachusetts list. ^iNaturalist
iNaturalist has 3,086 research-grade sightings of it in Minnesota, ranking #32 among the 110 flowers on our Minnesota list. ^iNaturalist

State flower gift ideas

This one is a regulated invasive plant, so here are state flower gifts instead.

🌱 Sample spot. Handmade gift picks from independent shops will appear here once our shop partnership is approved. These cards are placeholders, not real products.

Placeholder

State flower print
Gift pick coming soon
Placeholder

Birth-flower necklace
Gift pick coming soon
Placeholder

Wildflower seed favors
Gift pick coming soon
Placeholder

Botanical tea towel
Gift pick coming soon
Placeholder

Pressed-flower frame
Gift pick coming soon
Placeholder

Flower-garden mug
Gift pick coming soon

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (2,015 records)

Bloom time in each of our 11 states

State	Type	Peak bloom	Sightings*
Washington	Introduced	July–October	3,639
Massachusetts	Introduced	July–October	3,616
Minnesota	Introduced	July–October	3,086
Michigan	Introduced	July–October	1,750
Wisconsin	Introduced	July–September	1,619
Maine	Introduced	July–September	1,507
Montana	Introduced	July–October	876
Idaho	Introduced	July–October	798
New Hampshire	Introduced	July–October	626
Rhode Island	Introduced	July–September	603
South Dakota	Introduced	few records	280

Conservation status

Federal (U.S. ESA): Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. ^{USFWS ECOS}
NatureServe global: GNR Not yet ranked worldwide. ^NatureServe
Washington: No list Washington has no state law listing endangered or threatened plants (the Washington Natural Heritage Program's rare plant list isn't regulatory), so we show NatureServe's Washington ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Washington.
Massachusetts: Not listed Not on Massachusetts Endangered Species Act list (321 CMR 10.90). NatureServe: SNA, not applicable (usually because it isn't native there) in Massachusetts. ^{MESA list}
Minnesota: Not listed Not on Minnesota endangered, threatened and special concern plants (Minn. R. 6134.0300). NatureServe: SNA, not applicable (usually because it isn't native there) in Minnesota. ^{Minn. R. 6134.0300}
Michigan: Not listed Not on Michigan endangered and threatened plants (Mich. Admin. Code R 299.1028, eff. March 20, 2023). NatureServe: SNA, not applicable (usually because it isn't native there) in Michigan. ^{R 299.1028}
Wisconsin: Not listed Not on Wisconsin endangered and threatened species list (Wis. Admin. Code NR 27.03). NatureServe: SNA, not applicable (usually because it isn't native there) in Wisconsin. ^{NR 27.03}
Maine: Not listed Not on Maine Rare Plant List (Maine Natural Areas Program, 2021). E and T are Maine's official endangered and threatened plants (12 M.R.S.); SC and PE are tracking categories. NatureServe: SNA, not applicable (usually because it isn't native there) in Maine. ^{Maine rare plant list}
Montana: No list Montana has no state law listing endangered or threatened plants, so we show NatureServe's Montana ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Montana.
Idaho: No list Idaho has no state law listing endangered or threatened plants, so we show NatureServe's Idaho ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Idaho.
New Hampshire: Not listed Not on New Hampshire Official Rare Plants List (Ncr 312, eff. Jan 1, 2020). NatureServe: SNA, not applicable (usually because it isn't native there) in New Hampshire. ^{NH Ncr 312}
Rhode Island: Not listed Not on Rhode Island Rare Plants 2016 (RI Natural History Survey, from the RI Wildlife Action Plan; informational, Rhode Island has no state plant-protection listing law). NatureServe: SNA, not applicable (usually because it isn't native there) in Rhode Island. ^{RI rare plants 2016}
South Dakota: No list South Dakota's endangered and threatened list (ARSD 41:10:02) covers animals only, so we show NatureServe's South Dakota ranks for plants. NatureServe: SNA, not applicable (usually because it isn't native there) in South Dakota.
Rare elsewhere: No other U.S. state ranks it S1, S2, SH or SX.

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peoplePoisonous to people

NC State Extension lists it as poisonous to humans (severity: high). Poisonous parts: leaves. Symptoms they list: “Dried leaves have been used to make teas, but the current uses of this plant in teas, food, and medicine are almost non-existent. Thujone can be fatal in large quantities.” ^{NC State Extension}

For petsCan be a problem for horses

NC State Extension flags it as a problem for horses. It isn't on the ASPCA plant list. ^{NC State Extension}

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records common tansy in 45 states plus Washington, D.C.

AKMEVTNHWAIDMTNDMNILWIMINYRIMAORNVWYSDIAINOHPANJCTCAUTCONEMOKYWVVAMDDEAZNMKSARTNNCSCDCOKLAMSALGAHITXFL

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Dakota, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming; District of Columbia.

Washington counties with USDA records: Adams, Asotin, Benton, Chelan, Clallam, Clark, Columbia, Cowlitz, Ferry, Garfield, Grays Harbor, Island, King, Kitsap, Kittitas, Klickitat, Lewis, Lincoln, Mason, Okanogan, Pacific, Pend Oreille, Pierce, San Juan, Skagit, Skamania, Snohomish, Spokane, Stevens, Thurston, Wahkiakum, Walla Walla, Whatcom, Whitman, Yakima.

Massachusetts counties with USDA records: Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Hampshire, Middlesex, Nantucket, Norfolk, Plymouth, Suffolk, Worcester.

Minnesota counties with USDA records: Aitkin, Anoka, Becker, Brown, Carlton, Carver, Cass, Clay, Clearwater, Cook, Crow Wing, Dodge, Hennepin, Houston, Hubbard, Itasca, Kittson, Koochiching, Lake of the Woods, Le Sueur, Mahnomen, Morrison, Pennington, Pine, Pipestone, Polk, Ramsey, St. Louis, Todd, Wabasha, Wadena, Washington, Wilkin, Winona, Wright.

More Washington flowers

Common yarrow

Achillea millefolium

Native

🌼 Blooms in WA: May–September

White snakeroot

Ageratina altissima

Native

🌼 Blooms: August–October

Chicory

Cichorium intybus

Introduced

🌼 Blooms in WA: June–October

Sources

USDA, NRCS. PLANTS Database, profile TAVU.
iNaturalist, Tanacetum vulgare: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Tansy (lead quoted under CC BY-SA 4.0).
Washington: Washington State noxious weed list (WAC 16-750-005, -011, -015).
Massachusetts: Massachusetts Endangered Species Act list (321 CMR 10.90).
Massachusetts: Massachusetts Prohibited Plant List (MDAR) (Text from MDAR's 2023 scientific-name PDF (mass.gov blocks automated downloads); 2024-2026 additions listed on the mass.gov page: Alnus glutinosa, Pyrus calleryana, Miscanthus sinensis, Aralia elata, Rhodotypos scandens, Symplocos paniculata.).
Minnesota: Minnesota endangered, threatened and special concern plants (Minn. R. 6134.0300).
Minnesota: Minnesota Noxious Weed List (Minn. Stat. § 18.79; Minnesota Department of Agriculture, updated January 2026).
Michigan: Michigan endangered and threatened plants (Mich. Admin. Code R 299.1028, eff. March 20, 2023).
Michigan: Michigan prohibited and restricted species (NREPA Part 413 and the 2026 Invasive Species Order), as listed by Michigan's Invasive Species Program.
Wisconsin: Wisconsin endangered and threatened species list (Wis. Admin. Code NR 27.03).
Wisconsin: Wisconsin invasive species rule (Wis. Admin. Code NR 40.04 prohibited, NR 40.05 restricted).
Maine: Maine Rare Plant List (Maine Natural Areas Program, 2021). E and T are Maine's official endangered and threatened plants (12 M.R.S.); SC and PE are tracking categories.
Maine: Maine Do Not Sell invasive plant list (01-001 C.M.R. ch. 273).
Montana: Montana noxious weed list (Admin. R. Mont. 4.5.206–4.5.210).
Idaho: Idaho noxious weeds (IDAPA 02.06.09, Section 220).
New Hampshire: New Hampshire Official Rare Plants List (Ncr 312, eff. Jan 1, 2020).
New Hampshire: NH Prohibited Invasive Species List (Agr 3800, Table 3800.1).
Rhode Island: Rhode Island Rare Plants 2016 (RI Natural History Survey, from the RI Wildlife Action Plan; informational, Rhode Island has no state plant-protection listing law).
South Dakota: South Dakota statewide noxious weeds (ARSD 12:62:03:01.06).
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Tanacetum vulgare (global and state ranks).
Edibility and toxicity: NC State Extension.
Photo: Kathy Richardson via iNaturalist · CC BY 4.0 · resized.