Artichoke Thistle

Cynara cardunculus L.

Family: - Asteraceae.


Cynara is from the Greek kinara for artichoke, which is derived form kuon for dog or kynara for dog rose or dog thorn and refers to the sharp bracts surrounding the flower head.

Cardunculus is from the Latin Carduus meaning thistle and uncus meaning curved or claw like referring to claw like bracts around the flower head.

Artichoke Thistle refers to its resemblance of the Artichoke.

Other names:


Scotch Thistle

Spanish Artichoke

Wild Artichoke


A perennial or biennial spiny thistle with annual tops and a cluster of large bright purple flowers that are 5-8 cm in diameter during summer. The mature plant is erect, with stems 1-1.5 (2) m tall arising from a bushy rosette up to 2 m wide and tall. The stem is strongly ribbed and covered with downy grey hairs and usually single at the base and branched towards the top. The large, grey green leaves are deeply lobed and spiny with woolly hairs underneath.



Two. Oval with its widest point more towards the base and over 25mm long. It is greyish/green in colour with a distinct pale venation. There is no hypocotyl or epicotyl.

First leaves:

The first leaf is some 100 mm long by 25 mm wide with a short merging petiole. The margin carries a number of small spines and is scalloped between these.


Later leaves are progressively more deeply divided and carry long sharp spines on the lobes. The plant develops as a rosette with leaves up to 1000 mm long by 300 mm wide.

Petiole - Ribbed with spines.

Blade - Bright green to grey green on top, whitish below, deeply cut almost to the mid rib, into lance shaped lobes that are lobed again. Secondary lobes terminate in a long, yellow to orange, sharp spines, 15-35 mm long. Spines on the edges also. Slightly hairy on the upper surface, white and woolly hairs on the underside.

Stem leaves - Similar to rosette leaves but smaller.


Erect, stout, striped, grooved, spiny, to 200-2000 mm tall, branched near the top. Woolly hairs. Usually single stemmed but there may be up to 8 stems emerging from the crown.

Flower head:

Terminal on the branches, large, globular, usually over 45-70 mm and in some cases exceeding 130 mm in diameter. Usually around 16 heads on each plant but there may be up to 50.


Blue/purple. Tubular.

Bracts - Flower head surrounded by fleshy, strong, egg to lance shaped bracts that taper to a rigid, 10-50 mm long spine that is often purplish.

Ovary - Receptacle hairy.

'Petals' - Blue, lilac or whitish.

Stamens -

Anthers -


Achene. Hairless.


Pyramidal to egg shaped, 6-8 mm long by 3-4 mm wide, 4 sided , smooth, shiny, brown to black, spotted with lengthwise streaks, no wings. Hairless. Pappus a tuft of feather like, off-white bristles up to 40 mm long which are joined at the base.


Large fleshy tap root to 2000 mm long.

Key Characters:


Life cycle:

Perennial or biennial. Seeds may germinate at any time of the year. With most germination in the autumn after rains. The plants grow slowly over winter and forms a rosette that expands quickly in spring of the first year. Occasionally they may flower in their first summer. The top growth dies off over summer leaving a long, strong taproot. In its second and subsequent years a new rosette emerges from the root during autumn/winter and this develops into a cabbage like growth. Flowering stems emerge during spring and summer. Aerial growth dies and the dead flowering stems may remain standing well into the following season. Plants may live for many years.

The life cycle in Tasmania is not known.



By seed and root fragments.

Flowering times:

November to February in SA.

Seed Biology and Germination:

It has the heaviest thistle seed at 35 mg/seed (Michael, 1968).

Seed is probably introduced as a contaminant of other seeds or produce.

Vegetative Propagules:

This is one of the few perennial thistles, and regeneration can occur from crown or root fragments.


Cultivated and wild forms.

It is closely related to the Globe Artichoke (Cynara scolymus) and can hybridise with it.


Population Dynamics and Dispersal:

Seed is main form of spread. Wind may spread the about 20 metres from the parent plant. The seed is heavy and the pappus readily detaches. Movement assisted by sheep, cattle, mice, birds and in mud and water are more important.

Long distance dispersal is usually due to contamination of produce and disposal of cut flowers.

In cultivated areas spread by dragging of root fragments can cause local spread.

Origin and History:


First recorded in Adelaide in 1839 Tasmania in 1845.

It had naturalised in SA by 1879.



In Tasmania, odd plants have been found in and around Launceston.

In WA plants are eradicated as soon as they are found.



Warm temperate areas with an annual rainfall of 500-700 mm occurring mainly in winter.


Red brown clay loams and grey clay soils in NSW.

Black basalt soils in Victoria and red brown earths in SA.

Clay soils elsewhere.

Plant Associations:


An aggressive species capable of competing effectively in pasture. It deters stock from grazing infested areas. It is possible that some seed of Artichoke Thistle was included as a contaminant with Globe Artichoke seed.


Ornamental. The head is used for dried flower arrangements as a substitute for Scotch Thistle. Heads bearing viable seed have been intercepted being brought into Tasmania.

Food. Leaf bases of cultivated forms used as a vegetable or salad.

Leaves used as a rennin substitute for curdling milk.

Fodder. Hungry stock will eat it but normally it is sparingly grazed.

Produces large quantities of pollen for bees.


Weed of pasture, lucerne, waterways, coastal scrub lands, roadsides and disturbed areas.

Silage made from it is of low quality.

Forms dense, single species, inpenetrable stands of up to 50,000 plants/ha.

Invasive weed of the USA.


May cause contact dermatitis in some people.


Noxious weed of SA, TAS, VIC and WA.

Management and Control:

Graze with goats, increase cultivation, plant grasses and apply selective herbicides.


Tends to form patches that exclude other species and deter stock from grazing the area.

Eradication strategies:

Isolated plants can be removed manually but care must be taken to ensure much of the taproot is removed, otherwise it will re shoot.

Repeated cultivation each time new growth appears can be effective over a period of 2-3 years.

Grazing with goats reduces infestations and seed set.

A number of herbicides provide good control. Picloram containing products with its soil residual activity usually provides the most reliable control.

Glyphosate can be used as a cut stump treatment to reduce regrowth. Foliar sprays with glyphosate are most effective at bolting.

Herbicide resistance:

Biological Control:

Small birds feed on the seeds before they are ripe.

Related plants:

Globe artichoke (Cynara scolymus).

Plants of similar appearance:

Artichoke Thistle can be confused with Globe Artichoke. The leaves can distinguish the two, those of the Globe Artichoke being less deeply divided with broader lobes and without spines.


Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P100. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P933.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P726.

Hyde-Wyatt, B.H. and Morris, D.I. (1980) The Noxious and Secondary Weeds of Tasmania. (Tasmanian Department of Agriculture, Hobart, Tasmania). P28-29. Diagram.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #398.1.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P213-215. Photos.

Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P75. Photo.


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