About
Contact
Links
Electronic Flora of South Australia
Electronic Flora of South Australia
Census of SA Plants, Algae & Fungi
Identification tools
 

Electronic Flora of South Australia genus Fact Sheet

Family: Compositae
Carduus

Citation: L., Sp. Pl. 820 (1753).

Derivation: Latin carduus, a name applied by the Romans to various species of thistles.

Synonymy: Not Applicable

Common name: Thistles.

Description:
Spiny annual and perennial herbs; stems erect, with spiny wings; leaves basal and cauline, alternate, dentate to pinnatisect.

Capitula terminal, solitary or sessile in dense clusters, cylindrical to depressed-globose, homogamous; involucres cylindrical to broadly hemispherical; bracts rigid, herbaceous, spinetipped, imbricate in many unequal series; receptacle densely hairy; florets all tubular, bisexual, fertile; corolla narrow, only slightly widened upwards, 5-lobed, purple to pink; anthers sagittate at the base, with acute appendages at the apex; style branches linear, flattened, diverging at the apex only, without sterile appendages.

Achene ovoid, glabrous, striate; pappus of numerous barbellate bristles connate in a ring at the base and deciduous as a unit.

Distribution:  About 95 species in Europe, Asia and Africa.

Biology: No text

Key to Species:
1. Capitula hemispherical, 2-4 cm diam.; corollas c. 20 mm long
C. nutans 1.
1. Capitula cylindrical, c. 1 cm diam.; corollas 10-15 mm long
 
2. Capitula on short terete peduncles; intermediate bracts of the involucre with thickened minutely hairy margins
C pycnocephalus 2.
2. Capitula completely sessile; intermediate bracts of the involucre with glabrous scarious margins
C tenuiflorus 3.

Author: Not yet available


Disclaimer Copyright Disclaimer Copyright Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Government of South Australia Department for Environment and Water