knotweed japanese, invasive expansive species of dangerous plants leaf in river shrub bushes growth lush, leaves

asia background big biodiversity biomass blue botany bush bushes calamity contamination creek czech dangerous disaster eliminates environmental europe expansive fallopia flower gatecrasher green growth herbicides intruder invasive japan japanese japonica knotweed large leaf leaves lush mechanically nature neophyte plants reduces reynoutria river sachalinensis sakhalin shrub sky stream water wild wildflower