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

asia background big biodiversity biomass blue bush bushes calamity contamination creek czech dangerous disaster eliminates 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 tree water wild wildflower wood