We compared congeneric species of Impatiens with different origin and invasion status that occur in central Europe. Invasive Impatiens glandulifera produced high biomass in all treatments manipulating shading, moisture and nutrients, and in the control, exhibiting the 'Jack-and-master' strategy that makes it a strong competitor from germination onwards.
Plasticity and differentiation occurred in all the species tested and that along the continuum from plasticity to differentiation, the species at the plasticity end is the better invader. The most invasive species I. glandulifera appears to be highly plastic, whereas the other two less invasive species exhibited lower plasticity but rather strong population differentiation.
The invasive Impatiens species were taller and exhibited higher plasticity and differentiation than native I. noli-tangere. This suggests that the relative importance of the phenomena contributing to invasiveness appears to be species' specific.