Invasive
Describes a plant brought to a new region that spreads fast and harms the local plants and wildlife.
Also: invasive species
Most plants moved by people cause no trouble. A few escape, spread quickly and crowd out what was there before. Several began as garden flowers. Water hyacinth, from South America, now chokes lakes and rivers across Africa and Asia. Lantana, from tropical America, has spread through forests and grazing land in India, Australia and Africa. Many countries control which plants may be imported or sold, and gardeners are asked not to dump garden waste in the wild.