Phragmites

Phragmites, an invasive species of reed believed to have been introduced to North America from England, is often seen as a monster because the grass stalks grow three times the height of a man and drive out native plants and wildlife.  But some scientists suggest the plant is more of a Jekyll and Hyde, because while it is bad for plant diversity, it may be good at protecting shorelines from erosion caused by rising sea levels and climate change.