Artichoke Thistle, Cardoon, Scotch Thistle
Perennial forb to 2m tall. Spiny leaf stalks, leaf edges and flower heads. Leaves in a basal rosette and alternating up the stems, to 120cm long, to 350mm wide, slightly hairy above, hairy below, deeply divided into segments which are again divided, and tipped with yellow spines 5-35mm long. Flower heads with many blue, mauve, pink, or white 'petals'. Flower heads globular to oval, single at the ends of the stems. Noxious weed all NSW. Declared plant in SA. Noxious weed Vic.
Description and photo in G.M. Cunningham, WE Mulham, PL Milthorpe and J H Leigh (1981 and later printings) Plants of Western New South Wales page 726
Weeds of Australia Biosecurity Queensland Edition description: http://keyserver.lucidcentral.org/weeds/data/03030800-0b07-490a-8d04-0605030c0f01/media/Html/Cynara_cardunculus.htm