text: These results are consistent with those for a number of other invasive plant species (Callaway and Aschehoug 2000; Callaway and Ridenour 2004; Lankau et al. 2004; Wikstr√∂m et al. 2006; Callaway et al. 2008; He et al. 2009; Thorpe et al. 2009; Schaffner et al. 2010; Colvin and Gliessman 2011; Inderjit et al. 2011a; Kim and Lee 2011; Lamarque et al. 2011; Inderjit et al. 2011b; Svensson et al. 2013).