 Introduced plants can thereby evolve to grow taller, produce more biomass, and yield more viable offspring than their native counterparts, according to the hypothesis.Blossey and Nötzold tested their hypothesis on "Lythrum salicaria" (purple loosetrife) by potting seeds from plants growing in Ithaca, New York, U.S.A., and Lucelle, Switzerland.The seeds were allowed to germinate in a lab at Christian-Albrechts University in Kiel, northern Germany, and observed for two years.