hydrilla or waterthyme. hydrilla verticillata. invasive species in freshwater lake. aquatic weed. hydrilla disrupting aquatic

hydrilla verticillata aquatic plant water invasive species nature freshwater vegetation submerged lake pond waterthyme ecosystem weeds underwater environmental conservation issues green hydrocharitaceae forest algae thyme biological biomass control pest garden ornamental fresh problem weed leaves natural treatment environment clean fish background flora summer tree ecological food economic grass harm waterthyme verticillata lake weed disrupting ecosystems vegetation plants