Senecio gallicus, an annual plant of the Senecio genus and a member of the Asteraceae family is also one of those species who colonizes in isolated habitats where the environmental conditions could qualify as being difficult—widespread across southern France and the Iberian Peninsula in deserts and xeric shrublands, on steppes and salty dry coastal plains. S. gallicus is playing a predominant role in shaping patterns of genetic structure by presenting models of historical associations among population rather than patterns of ongoing gene flow.