Further naturalised Cactaceae in northeastern Iberian Peninsula

During the floristic work carried out in 2004 in the Baix Camp region of Tarragona (NE Spain) we found four new species of alien naturalised Cactaceae. Of these, three are reported for the second time from Europe and the other is new to Catalonia region. Southern Catalonia, with eleven species of Cactaceae, harbours the highest diversity of the family in Europe. Our results demonstrate that this diversity is even higher than previously believed. The introduction of these exotic taxa is, once again, due to the development of gardening based exclusively on foreign elements, to the unscrupulous and uncontrolled dumping of their remains in the natural environment, and to the existence of a favourable climate.