ABSTRACT
Chondrilla juncea L. (Compositae) is one of the worst weeds in the wheat-growing areas of countries as far away as Australia and Argentina. The species is thought to have evolved in central Eurasia and then spread to the West, being found in all Mediterranean Europe. 25 , 26 The first recorded appearance outside Europe was in Washington, D.C. in 1896. In Australia it was first reported in 1918, 16 possibly introduced with hay from the U.S. 17 Since then it has spread among the wheat-growing areas, especially in the eastern states (New South Wales, Victoria, South Australia), but it is found as isolated patches in Western Australia. 18 In Argentina, its appearance was first recorded in 1977, 24 in the southwest of the province of Buenos Aires, and it is suspected that it now covers more than 50,000 ha. 2
