FNPS Plant Database

Cirsium horridulum

Purple thistle, yellow thistle
  • Photo by: Mark Hutchinson, Hernando Chapter, FNPS
  • Photo by: Mark Hutchinson, Hernando Chapter, FNPS
  • Photo by: Mark Hutchinson, Hernando Chapter, FNPS
  • Photo by: John Bradford, Martin County Chapter FNPS
  • Photo by: John Bradford, Martin County Chapter FNPS

Nomenclature

Common Name:

Purple thistle, yellow thistle

Synonym(s):

Genus species:

Cirsium horridulum

Family:

Asteraceae (Compositae)

Plant Specifics

Form:

flower

Size:

1-4 ft tall by 1-2 ft wide

Life Span:

Long-lived perennial

Flower Color:

regionally variable: white, pink, purple, yellow

Fruit Color:

white

Phenology:

Overwinters as a basal rosette. Blooms in spring.

Noted For:

Showy Flowers, Thorns, Interesting Foliage

Landscaping

Recommended Uses:

Natural landscapes including meadows and butterfly gardens.

Considerations:

Purple thistle is a thorny plant - be very careful when handling.

Availability:

Seed

Propagation:

Readily self seeds. Following pollination the flower head can be bagged to collect the seed head which follows.

Light:

Full Sun, Part Sun

Moisture Tolerance:

Always Flooded---------------------------------Extremely Dry

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Somewhat moist, no flooding -to- Somewhat long very dry periods

Salt Water Flooding Tolerance:

Unknown

Salt Spray/Salty Soil Tolerance:

Some tolerance to salty wind but not direct salt spray

Soil or Other Substrate:

Sand

Soil pH:

6.1 - 7.8

Suitable to Grow In:

8A,8B,9A,9B,10A,10B

USDA zones are based on the average annual extreme minimum winter temperature.

Don't know your zone? Click here to search by zip code.

Ecology

Wildlife:

Pollinators, Butterflies, Caterpillars, Birds



  • Larval host to little metalmark ( Calephelis virginiensis ) and painted lady ( Vanessa cardui ) butterflies.


  • Nectar source for native butterflies and bumblebees.  Bees documented in Florida include   Evylaeus pectoralis, Halictus ligatus, Lithurgzcs gibbosus, Megachile brevis pseudobrevis , and the non-native Apis mellifera (honeybee) (Deyrup et al. 2002).


  • Beetles eat the flowers. 


  • Provides nesting material for some native bees (based on information provided by the Xerces Society to the Lady Bird Johnson Wildflower Center )


The seeds are rich in oil, an important food source for seed-eating birds. 

Native Habitats:

coastal plain, edges of salt marshes, pinewoods, prairies and disturbed areas.

Natural Range in Florida:

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Comments:

Ethnobotany:

Members of the Seminole tribe used parts of this plant to make blowgun darts.

General Comments:

Citations:

Eckberg, J., E. Lee-Mader, J. Hopwood, S. Foltz Jordan, and B. Borders. (2017). Native Thistles: A Conservation Practitioner's Guide. Production Methods, and Habitat Restoration Opportunities. The Xerces Society for Invertebrate Conservation, Portland, OR.


Gann, G.D., C.J. Abbott, C.G. Stocking, K.N. Hines, and collaborators. (2001+), Natives For Your Neighborhood. ( https://www.regionalconservation.org/beta/nfyn/plantdetail.asp?tx=Cirshorr ). Accessed 2026. The Institute for Regional Conservation. Delray Beach, Florida.


Hammer, Roger. (2015). Attracting Hummingbirds and Butterflies in Tropical Florida. University Press of Florida, Gainesville.


Lady Bird Johnson Wildflower Center. (2022). Plant Database: Cirsium horridulum (Bristle Thistle). ( https://www.wildflower.org/plants/result.php?id_plant=CIHO2 ). Accessed 2026. Lady Bird Johnson Wildflower Center, Austin, TX.


Wunderlin, R. P., B. F. Hansen, A. R. Franck, and F. B. Essig. (1999+). Atlas of Florida Plants. ( https://florida.plantatlas.usf.edu/ ). [S. M. Landry and K. N. Campbell (application development), USF Water Institute.] Institute for Systematic Botany, University of South Florida, Tampa.

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