Bloomipedia
Arizona thistle (Cirsium arizonicum)
Photo: Lexi Amico via iNaturalist · CC BY 4.0 · resized

Flower profile

Arizona thistle

Cirsium arizonicum

Arizona thistle (Cirsium arizonicum) is a flowering plant in the Asteraceae family, native in the lower 48 states, blooming mostly June–September across the U.S.

Native to Arizona

Arizona thistle is a wildflower that USDA PLANTS lists as native in the lower 48 states. In Arizona it's most often seen in bloom in June–September.

5states where USDA records it
1,109AZ sightings*
1,976U.S. sightings*

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

On our lists for: Arizona

Quick look

Cirsium arizonicum, the Arizona thistle, is a North American species of thistle in the family Asteraceae, native to the southwestern United States and northwestern Mexico. It has been found in Arizona, southeastern California, New Mexico, Nevada, Colorado, Utah, Sonora, and northwestern Chihuahua.

  • 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 native in the lower 48 states and records it in 5 states. USDA PLANTS
  • NatureServe lists it as native to Arizona. NatureServe
  • In Arizona, most iNaturalist sightings of it in flower come in June–September. iNaturalist
  • iNaturalist has 1,109 research-grade sightings of it in Arizona, ranking #96 among the 132 flowers on our Arizona list. iNaturalist

When does it bloom?

In Arizona, most flowering sightings come in June–September.

Flowering records by month in Arizona (iNaturalist research-grade observations marked “Flowering”) (124 records)

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
Arizona
Not listed Not on Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025). NatureServe: SNR, not yet ranked in Arizona. AAC R3-3 App. A
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.

🌿 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 Arizona thistle in 5 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Arizona, California, Nevada, New Mexico, Utah.

Arizona counties with USDA records: Apache, Cochise, Coconino, Gila, Mohave, Navajo, Pima, Santa Cruz.

Names, range and relatives

Other scientific names (synonyms in USDA PLANTS): Cirsium nidulum, Cnicus arizonicus.

County records: USDA PLANTS lists it in 28 counties across 5 states; the most are in Utah (10), Arizona (8), California (4).

Other Cirsium on Bloomipedia (12): Bull thistle, Creeping thistle, Bristle thistle, Cobwebby thistle, Field thistle, Texas thistle, Wavyleaf thistle, Tall thistle, Elk thistle, New Mexico thistle.

More from the Asteraceae family (212 on Bloomipedia; most observed first): Common yarrow, Goldenrods, White snakeroot, Sunflowers, Chicory, Black-eyed Susan, Common dandelion, Firewheel.

More Arizona flowers

Brittlebush (Encelia farinosa)

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🌼 Blooms in AZ: January–December
Stinknet (Oncosiphon pilulifer)

Stinknet

Oncosiphon pilulifer

🌼 Blooms in AZ: March–May
Desert marigold (Baileya multiradiata)

Desert marigold

Baileya multiradiata

Native

🌼 Blooms in AZ: March–May

Sources