Blue cattail (T. x glauca) is a mostly sterile but highly competitive (Tuchman et al. 2009) and invasive hybrid between the native Typha latifolia and the introduced Typha angustifolia. It is present in the eastern US and Canada, and in some western states (USDA 2010). It is considered introduced in BC (BC Conservation Data Center 2010) though some sources list it as native in North America (e.g. USDA 2010). It occurs wherever the two parent species are present and is morphologically intermediate between the two (Smith 2010). Like its parents, it spreads by rhizomes and fragments, and can form large clonal populations that out-compete the parent species (Smith 2010). Research has shown that in areas where it has invaded there is lower species diversity and higher levels of nutrients, possibly indicating a change in wetland function (Angeloni 2006). It is typically found in high nutrient disturbed habitats (Olson et al. 2009) with unstable water levels. For more information on cattail hybrids, please refer to the Flora North America treatment.