[Untitled]

Field survey in Catalonia (Spain) has increased the known distribution and the number of populations of the South African daisy Senecio pterophorus DC. in the Iberian Peninsula and mainland Europe. The species colonizes relatively disturbed habitats such as river beds, road borders and disturbed helm-oak communities with no limitation in light and water. The analysis of population structure related to habitat type has revealed that in riparian and ruderal areas populations are large and well-established, with a large number of members per age class. However, in disturbed forests populations have only a few scattered adults. Senecio pterophorus also shows great morphological plasticity related with habitat type: in open environments plants are shorter, adopt a spherical habit, and have smaller leaves than in forests, where they are taller and have leaves twice in size. This species may be considered as invasive in the Iberian Peninsula and mainland Europe, where it has rapidly spread in recent years. Furthermore, we suggest that S. pterophorus may be a threat to native species and habitat diversity as occurs in Australia, where the species displaces the native plants and hybridizes with some native Senecio species.