[UCANR] Origins and Introduction: Artichoke thistle is native to the Mediterranean region but occurs as an aggressive and troublesome weed in grazing lands of Australia and New Zealand. ... The initial establishment of artichoke thistle in some parts of California can be attributed to the introduction and cultivation of its close relatives, globe artichoke Cynara scolymus L. and cardoon C. cardunculus. ... Numerous early California plant observers mentioned either the cultivated artichoke or cardoon as escaping from cultivation and occurring as a localized weed. ... Many of the early artichoke thistle infestations in the state probably originated in this fashion, being first planted for food at missions and ranchos and by other early settlers, and then later escaping as the more aggressive and stoutly spiny forms that were well adapted as rangeland weeds. (link added by Jessica Johnston)