A casual alien plant new to Mediterranean Europe: Ceiba speciosa(Malvaceae) in the suburban area of Palermo (NW Sicily, Italy)

The abiotic and biotic characteristics of the first sites where floss silktree behaves as a casual alien plant in the Mediterranean Europe aredescribed. The species was probably first planted in botanical gardens ofsouthern France few decades before mid XIX century. It was introducedin Palermo in 1896, a city which appears to match very well its climaticrequirements. According to the available information on its biology andecology in both its original and secondary range, the floss silk tree shouldnot become an invasive alien plant in the Mediterranean. Nevertheless,several gaps need to be filled in order to increase our understanding offuture trends of Ceiba speciosa in southern Europe, in particular, theeventual role of pollinators and seed dispersers outside the species’ naturalrange.