Common Name:

purple thistle, yellow thistle

Synonym(s):

Genus species:

Cirsium horridulum

Family:

Asteraceae (Compositae)

Form:

flower

Size:

1-4 ft tall by 1-2 ft wide

Life Span:

biennial

Flower Color:

regionally variable: white, pink, purple, yellow

Fruit Color:

white

Phenology:

overwinters as a basal rosette; blooms in spring

Noted For:

Recommended Uses:

Natural landscapes including meadows and butterfly gardens.

Considerations:

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

Availability:

Propagation:

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

Light:

Moisture Tolerance:

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

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

Salt Water Flooding Tolerance:

Not salt tolerant of inundation by salty or brackish water

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, 11

Wildlife:

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

Native Habitats:

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

Natural Range in Florida:

Visit the USF Libraries Atlas of Florida Plants

Ethnobotany:

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

General Comments:

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