Carduus pycnocephalus L.

Slender Thistle

Sp. Pl., edn 2, 1151 (1763) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Naturalised

Annual to 80 cm high; stems with discontinuous wings to c. 5 mm wide and spinose lobes to 5 mm wide, cobwebbed. Basal leaves in a sparse rosette, oblanceolate in outline, 5–20 cm long, 2–8 cm wide, deeply pinnatisect, margins spiny, upper surface green and pubescent, lower surface white-cobwebbed; cauline leaves similar but smaller, stem-clasping. Inflorescence of 1–3 capitula in terminal clusters; capitula cylindric, erect, c. 10 mm diam.; peduncles 3–40 mm long, terete; involucral bracts linear-lanceolate, to 20 mm long, erect; dorsal surface of intermediate involucral bracts covered with minute antrorse hairs; inner bracts slightly shorter than florets. Corolla 10–17 mm long, pinkish-purple. Cypselas 4–5 mm long; pappus bristles subequal, 10–14 mm long. Flowers mainly spring and summer.

*CVU, *DunT, *EGL, *EGU, *GipP, *Glep, *Gold, *GGr, *HNF, *HSF, *LoM, *MuF, *MuM, *MSB, *NIS, *OtP, *Strz, *VAlp, *VRiv, *VVP, *WaP, *Wim. Also naturalised WA, SA, Qld, NSW, ACT, Tas., New Zealand. Native to Europe. A widespread and common weed, largely co-extensive with C. tenuiflorus and found in similar situations; declared a noxious weed in Victoria.

Source: Jeanes, J.A. (1999). Asteraceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 4, Cornaceae to Asteraceae. Inkata Press, Melbourne.
Hero image
Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder Asteranae
order Asterales
family Asteraceae
genus Carduus
Higher taxa


Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <>. Find Carduus pycnocephalus in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Carduus pycnocephalus in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Lowan Mallee present naturalised
Murray Mallee present naturalised
Wimmera present naturalised
Glenelg Plain present naturalised
Victorian Volcanic Plain present naturalised
Victorian Riverina present naturalised
Murray Scroll Belt present naturalised
Murray Fans present naturalised
Gippsland Plain present naturalised
Otway Plain present naturalised
Warrnambool Plain present naturalised
Goldfields present naturalised
Central Victorian Uplands present naturalised
Greater Grampians present naturalised
Dundas Tablelands present naturalised
Northern Inland Slopes present naturalised
East Gippsland Lowlands present naturalised
East Gippsland Uplands present naturalised
Highlands-Southern Fall present naturalised
Highlands-Northern Fall present naturalised
Strzelecki Ranges present naturalised
Victorian Alps present naturalised

State distribution

Distribution map
Western Australia
South Australia
New South Wales
Australian Capital Territory