Compositae as invaders: better than the others?

Records of alien species in 26 local floras all over the globe were analysed. The representation of Compositae in these floras was assessed and compared with that of other families contributing most to the alien floras. The Compositae were present in all alien floras and by contributing 13.5 % on average represent the second most represented family (after Gramineae). Comparison of their performance in alien floras (13.5 %) with their proportion of the world flora (8.4 %) indicates that they are over-represented among aliens. When using a relative measure, i.e. relating species numbers to the global species pool in a family, Compositae rank about average. However, the family is remarkably successful in terms of dispersal and establishment.