Weed Identification

Australia > > Spear thistle

Spear thistle

Cirsium vulgare

Alternative Name(s): Black Thistle, Bull Thistle, Scotch Thistle

Family: Asteraceae

Form: Herb

Origin: Native of Europe, Asia and northern Africa.

Flowers/Seedhead: Many flowers (florets) in heads 35 cm long; florets 2.53.5 cm long. Flowers spring to autumn.

Description: Erect annual or biennial thistle to 1.5 m high. Stems winged with spines on the wings, cobwebby. Leaves lanceolate to ovate in outline, upper surface dark green and bristly, lower surface white woolly; basal leaves to 45 cm long in a rosette, initial leaves less lobed than later leaves, margins wavy to toothed, narrowing to the base; stem leaves to 25 cm long, lobed, not on a stalk and base continuing down stems as wings. Seeds 35 mm long, grey with longitudinal darker markings, smooth.

Distinguishing features: Distinguished by roots not rhizomatous; leaves with spines on margins; heads 25 cm wide, solitary or in groups of 24 at the end of branches; florets all tubular, pinkish-purple, bisexual; bracts around heads spine-tipped; seeds compressed topped by numerous feather-like bristles 2030 mm long; area where seeds attach to the head with bristle-like scales.

Dispersal: Spread by movement of seed, by wind, water or mud.


Heads with mauve florets
& long spiny bracts,
Blacktown, NSW, Oct
photos G. Sainty, J. R. Hosking, J. J. Dellow

Notes: Widespread and common in crop and non-crop situations; found especially on high fertility soils. Not palatable to stock and may be the only plant remaining in heavily grazed paddocks. Spines in wool cause difficulty in shearing and this plant is an important component of vegetable fault of wool. Cirsium vulgare is naturalised in temperate areas around the world.

References:

    Noxious Weeds of Australia. W. Parsons and E. Cuthbertson, 1992, pp 209212. World Weeds: Natural Histories and Distribution. Holm et al., 1997, pages 207215.

Web References: Search Australian web sites for further information on this weed.


Heads & erect habit
Newington, NSW
August

Top: Seedlings
Bottom: Rosette

Seeds & pappus

Infestation

This weed has been included in the WEEDeck field guide as card H71

More information about WEEDeck is available from Sainty & Associates Pty. Ltd.

 

Australia > > Spear thistle

BACK

National Weeds Strategy
Telephone: (03) 6344 9657
Fax: (03) 6343 1877
Email: jthorp@weeds.org.au

Privacy Statement

Legal Notice

Site Design - Computer Support Tasmania
Australian Weeds Committee