Bloomipedia
Creeping thistle (Cirsium arvense)
Photo: Michael via iNaturalist · CC BY 4.0 · resized

Flower profile

Creeping thistle

Cirsium arvense

Introduced in the lower 48

Creeping thistle is a wildflower that USDA PLANTS lists as introduced in the lower 48 states. It's on our flower lists for 21 states, and across the U.S. it's most often seen in bloom in June–September.

42states
21of our state lists
51,077U.S. sightings*

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

On our lists for: Colorado, Delaware, Idaho, Illinois, Indiana, Iowa, Maine, Maryland, Michigan, Minnesota, Montana, Nebraska, New Jersey, New York, North Dakota, Ohio, Pennsylvania, South Dakota, Washington, Wisconsin, Wyoming

🚫
Regulated invasive plant in Pennsylvania, New York, Washington, Colorado, Wisconsin, Minnesota, Montana, Iowa, South Dakota, Wyoming, Idaho, North Dakota and Nebraska. It's on those states' official invasive plant lists (Pennsylvania: Class B noxious weed; New York: Prohibited invasive species (6 NYCRR § 575.3); Washington: Class C noxious weed; Colorado: List B noxious weed; Wisconsin: Restricted invasive species; Minnesota: Prohibited noxious weed (control); Montana: Priority 2B noxious weed; Iowa: Primary noxious weed; South Dakota: Statewide noxious weed; Wyoming: State designated noxious weed; Idaho: Statewide containment noxious weed; North Dakota: State noxious weed (landowners must control it); Nebraska: Noxious weed (landowners must control it)). Please don't plant or share it there. PA noxious weed list 6 NYCRR Part 575 WAC 16-750 8 CCR 1206-2 NR 40 MN noxious weed list ARM 4.5.206–210 Iowa Code § 317.1A ARSD 12:62:03:01.06 WY designated noxious weeds IDAPA 02.06.09 NDAC 7-06-01-02 25 NAC 10-001.02

Quick look

Cirsium arvense is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and western Asia, northern Africa and widely introduced elsewhere. The standard English name in its native area is creeping thistle. It is also commonly misnomered as Canada thistle and sometimes as field thistle.

  • 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 42 states. USDA PLANTS
  • In Pennsylvania, most iNaturalist sightings of it in flower come in June–October. iNaturalist
  • In Ohio, most iNaturalist sightings of it in flower come in June–September. iNaturalist
  • iNaturalist has 5,463 research-grade sightings of it in Pennsylvania, ranking #25 among the 111 flowers on our Pennsylvania list. iNaturalist
  • iNaturalist has 4,875 research-grade sightings of it in Ohio, ranking #30 among the 109 flowers on our Ohio list. iNaturalist
  • iNaturalist has 3,845 research-grade sightings of it in New York, ranking #56 among the 109 flowers on our New York list. iNaturalist

State flower gift ideas

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

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (3,163 records)
Bloom time in each of our 21 states
StateTypePeak bloomSightings*
PennsylvaniaIntroducedJune–October5,463
OhioIntroducedJune–September4,875
New YorkIntroducedJune–September3,845
WashingtonIntroducedJune–September3,841
ColoradoIntroducedJune–October3,531
WisconsinIntroducedJune–September3,178
MichiganIntroducedJune–October3,046
MinnesotaIntroducedJune–September3,042
IllinoisIntroducedJune–August2,814
MarylandIntroducedMay–September2,339
New JerseyIntroducedMay–September2,194
IndianaIntroducedJune–September1,537
MaineIntroducedJuly–October857
MontanaIntroducedfew records774
IowaIntroducedJune–September722
South DakotaIntroducedfew records706
WyomingIntroducedJuly–October689
IdahoIntroducedfew records569
North DakotaIntroducedJuly–September503
DelawareIntroducedfew records315
NebraskaIntroducedfew records193

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
G5 Secure worldwide. NatureServe
Pennsylvania
Not listed Not on Pennsylvania classified native plants (17 Pa. Code Ch. 45, Subchapter B, as amended 2023). NatureServe: SNA, not applicable (usually because it isn't native there) in Pennsylvania. 17 Pa. Code Ch. 45
Ohio
Not listed Not on Ohio endangered and threatened plants (Ohio Adm. Code 1501:18-1-03, eff. Dec. 26, 2024). NatureServe: SNA, not applicable (usually because it isn't native there) in Ohio. OAC 1501:18-1-03
New York
Not listed Not on New York protected native plants (6 NYCRR § 193.3). NatureServe: SNA, not applicable (usually because it isn't native there) in New York. 6 NYCRR § 193.3
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.
Colorado
No list Colorado has no state law listing endangered or threatened plants, so we show NatureServe's Colorado ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Colorado.
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
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
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
Illinois
Not listed Not on Illinois List of Endangered and Threatened Flora (17 Ill. Adm. Code 1050), per the Endangered Species Protection Board's 2025 checklist. NatureServe: SNA, not applicable (usually because it isn't native there) in Illinois. IL E&T checklist 2025
Maryland
Not listed Not on Maryland threatened and endangered plants (COMAR 08.03.08.05, .06 and .08). NatureServe: SNA, not applicable (usually because it isn't native there) in Maryland. COMAR 08.03.08
New Jersey
Not listed Not on New Jersey Endangered Plant Species List (N.J.A.C. 7:5C-5.1). NatureServe: SNA, not applicable (usually because it isn't native there) in New Jersey. N.J.A.C. 7:5C-5.1
Indiana
No list Indiana has no state law listing endangered or threatened plants (the DNR keeps a rare plant list, but it isn't regulatory), so we show NatureServe's Indiana ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Indiana.
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.
Iowa
Not listed Not on Iowa endangered, threatened and special concern plants (Iowa Admin. Code r. 571-77.3). NatureServe: SNA, not applicable (usually because it isn't native there) in Iowa. IAC 571-77.3
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.
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.
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.
North Dakota
No list North Dakota has no state law listing endangered or threatened plants, so we show NatureServe's North Dakota ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in North Dakota.
Delaware
Not listed Not on Rare and Uncommon Plants of Delaware (DNREC, 2024; informational, Delaware has no state plant-protection list). NatureServe: SNA, not applicable (usually because it isn't native there) in Delaware. DE rare plants 2024
Nebraska
Not listed Not on Nebraska threatened and endangered species (163 Neb. Admin. Code ch. 4, § 004). NatureServe: SNA, not applicable (usually because it isn't native there) in Nebraska. 163 NAC 4-004
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 edibility or poison notes on its page), USDA PLANTS) say whether it's edible or poisonous for people. NC State Extension

For petsNot well documented

It isn't on the ASPCA plant list, and NC State Extension doesn't flag it for pets.

🌿 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 creeping thistle in 42 states plus Washington, D.C.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, 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 Dakota, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming; District of Columbia.

Pennsylvania counties with USDA records: Adams, Allegheny, Armstrong, Beaver, Bedford, Berks, Blair, Bradford, Bucks, Butler, Cambria, Cameron, Carbon, Centre, Chester, Clarion, Clearfield, Clinton, Columbia, Crawford, Cumberland, Dauphin, Delaware, Elk, Erie, Fayette, Forest, Franklin, Fulton, Greene, Huntingdon, Indiana, Juniata, Lackawanna, Lancaster, Lawrence, Lebanon, Lehigh, Luzerne, Lycoming, McKean, Mercer, Monroe, Montgomery, Montour, Northampton, Northumberland, Perry, Philadelphia, Potter, Schuylkill, Somerset, Sullivan, Susquehanna, Tioga, Venango, Warren, Washington, Wayne, Westmoreland, York.

Ohio counties with USDA records: Adams, Ashtabula, Athens, Auglaize, Belmont, Carroll, Champaign, Clark, Clinton, Coshocton, Crawford, Cuyahoga, Darke, Delaware, Erie, Fairfield, Fayette, Franklin, Geauga, Greene, Guernsey, Hamilton, Harrison, Henry, Highland, Hocking, Holmes, Huron, Jefferson, Knox, Lake, Lawrence, Licking, Logan, Lorain, Lucas, Madison, Mahoning, Marion, Medina, Miami, Morgan, Morrow, Muskingum, Ottawa, Paulding, Perry, Pike, Portage, Richland, Ross, Sandusky, Shelby, Stark, Summit, Trumbull, Tuscarawas, Union, Vinton, Washington, Wayne, Wood.

New York counties with USDA records: Albany, Allegany, Bronx, Cattaraugus, Columbia, Delaware, Erie, Essex, Greene, Jefferson, Kings, Lewis, Monroe, Nassau, New York, Onondaga, Orange, Oswego, Putnam, Queens, Richmond, Schenectady, Schoharie, St. Lawrence, Suffolk, Sullivan, Tompkins, Ulster, Washington, Westchester, Wyoming.

More Pennsylvania flowers

Sources