Flower profile

Spotted knapweed

Centaurea stoebe

Introduced in the lower 48

Spotted knapweed is a wildflower that USDA PLANTS lists as introduced in the lower 48 states. It's on our flower lists for 6 states, and across the U.S. it's most often seen in bloom in June–October.

46states

6of our state lists

18,806U.S. sightings*

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

On our lists for: Idaho, Michigan, Minnesota, Montana, Wisconsin, Wyoming

🚫

Regulated invasive plant in Minnesota, Montana and Idaho. It's on those states' official invasive plant lists (Minnesota: Prohibited noxious weed (control); Montana: Priority 2B noxious weed; Idaho: Statewide containment noxious weed). Please don't plant or share it there. ^{MN noxious weed list ARM 4.5.206–210 IDAPA 02.06.09}

Quick look

Centaurea stoebe, the spotted knapweed or panicled knapweed, is a species of Centaurea native to eastern Europe, although it has spread to North America, where it is considered an invasive species. It forms a tumbleweed, helping to increase the species' reach, and the seeds are also enabled by a feathery pappus.
From Wikipedia's article Centaurea stoebe, CC BY-SA 4.0.

It belongs to the Asteraceae family. ^iNaturalist
USDA PLANTS describes it as an herb (forb) with a biennial, perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as introduced in the lower 48 states and records it in 46 states. ^{USDA PLANTS}
NatureServe lists it as not native to Michigan, Wisconsin, Minnesota, Montana, Idaho and Wyoming. ^NatureServe
In Michigan, most iNaturalist sightings of it in flower come in June–October. ^iNaturalist
In Wisconsin, most iNaturalist sightings of it in flower come in July–October. ^iNaturalist
iNaturalist has 3,276 research-grade sightings of it in Michigan, ranking #38 among the 111 flowers on our Michigan list. ^iNaturalist
iNaturalist has 2,295 research-grade sightings of it in Wisconsin, ranking #57 among the 109 flowers on our Wisconsin list. ^iNaturalist
iNaturalist has 2,002 research-grade sightings of it in Minnesota, ranking #60 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.

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State flower print
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Birth-flower necklace
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Wildflower seed favors
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Botanical tea towel
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Pressed-flower frame
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Flower-garden mug
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When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (2,401 records)

Bloom time in each of our 6 states

State	Type	Peak bloom	Sightings*
Michigan	Introduced	June–October	3,276
Wisconsin	Introduced	July–October	2,295
Minnesota	Introduced	July–October	2,002
Montana	Introduced	July–October	1,362
Idaho	Introduced	July–October	489
Wyoming	Introduced	July–October	419

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
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}
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}
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.
Wyoming: No list Wyoming has no state law listing endangered or threatened plants, so we show NatureServe's Wyoming ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Wyoming.
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 peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list. For context only: ASPCA lists a related species, Centaurea cyanus (“Bachelors Buttons”), as non-toxic to dogs and cats. That doesn't tell us about this species, so keep pets away to be safe. ^ASPCA

🌿 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 spotted knapweed in 46 states.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

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

Michigan counties with USDA records: Alcona, Alger, Allegan, Alpena, Antrim, Arenac, Baraga, Barry, Benzie, Berrien, Calhoun, Charlevoix, Cheboygan, Chippewa, Clare, Clinton, Crawford, Delta, Dickinson, Emmet, Gladwin, Gogebic, Grand Traverse, Gratiot, Hillsdale, Houghton, Huron, Ingham, Iosco, Iron, Isabella, Jackson, Kalamazoo, Kalkaska, Kent, Keweenaw, Lake, Lapeer, Leelanau, Lenawee, Livingston, Luce, Mackinac, Macomb, Manistee, Marquette, Mason, Mecosta, Menominee, Midland, Monroe, Montcalm, Montmorency, Muskegon, Newaygo, Oakland, Oceana, Ogemaw, Ontonagon, Osceola, Oscoda, Otsego, Ottawa, Presque Isle, Roscommon, Saginaw, Schoolcraft, St. Clair, St. Joseph, Tuscola, Van Buren, Washtenaw, Wayne, Wexford.

Wisconsin counties with USDA records: Adams, Ashland, Bayfield, Brown, Calumet, Chippewa, Columbia, Dane, Dodge, Door, Douglas, Florence, Fond du Lac, Forest, Grant, Green, Iowa, Iron, Jackson, Jefferson, Kewaunee, Lafayette, Lincoln, Manitowoc, Marathon, Marinette, Milwaukee, Monroe, Oconto, Oneida, Pierce, Portage, Richland, Rock, Rusk, Sauk, Sawyer, Shawano, Sheboygan, Vilas, Walworth, Washburn, Waukesha, Waupaca, Waushara, Wood.

Minnesota counties with USDA records: Becker, Benton, Cass, Chisago, Clay, Clearwater, Cook, Dakota, Hubbard, Kandiyohi, Kittson, Koochiching, Mahnomen, Otter Tail, Pine, Polk, Ramsey, Sherburne, St. Louis, Todd, Washington.

More Michigan flowers

Common yarrow

Achillea millefolium

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🌼 Blooms in MI: June–October

White snakeroot

Ageratina altissima

Native

🌼 Blooms in MI: August–October

Chicory

Cichorium intybus

Introduced

🌼 Blooms in MI: June–October

Sources

USDA, NRCS. PLANTS Database, profile CEST8.
iNaturalist, Centaurea stoebe: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Centaurea stoebe (lead quoted under CC BY-SA 4.0).
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).
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).
Montana: Montana noxious weed list (Admin. R. Mont. 4.5.206–4.5.210).
Idaho: Idaho noxious weeds (IDAPA 02.06.09, Section 220).
Wyoming: Wyoming state designated noxious weeds (W.S. 11-5-102(a)(xi)), as listed by the Wyoming Weed & Pest Council.
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Centaurea stoebe (global and state ranks).
Edibility and toxicity: ASPCA.
Photo: Jonathan Layman via iNaturalist · CC BY 4.0 · resized.