Phragmites australis (Cav.) Steud. is one of the most dominant and common species in wetland ecosystems from temperate regions worldwide [1][2][3]. It is tolerant to a broad ecological range, colonizing different habitat types, such as riverbanks, ditches, littoral zones of lakes, fens, bogs and salt-marshes. This sub-cosmopolite species can grow in oligotrophic to eutrophic conditions, but it seems to be favoured in nutrient-rich sites [4]. The common reed can also withstand different pollutants, including heavy metals. For this reason, it is often used for the treatment of industrial or agricultural wastewaters [5-9], for phytoremediation [10-12] and even for the removal of harmful microorganisms due to its allelopathic effect [13].In some areas of the world this grass is regarded as an aggressive invasive species [14][15][16][17]. The phenomenon is prominent in the USA where the Eurasian subspecies P. australis subsp. australis outcompetes the native, recently described, P. australis subsp. americanus Saltonstall, P.M. Peterson & Soreng, displacing the authoctonous populations [18]. For this reason, in N-America and Canada P. australis subsp. australis was included among the highest priority invasive species [19][20][21][22][23][24]. On the other side, reed beds represent valuable ecosystems for biodiversity conservation, although they are both usually