Common cordgrass originated in southern England around 1870: an allotetraploidal offspring of European small cordgrass and American smooth cordgrass. (Allopolyploidy is polyploidy of chromosomes of distinct species.) Transposable elements played a key role in the creation of this saltational hybrid.
Common cordgrass is a quick-growing sturdy grass that forms large, thick colonies on coastal salt marshes. With its dense root systems binding mud and increasing silt deposits, common cordgrass was seen as a means to control coastal erosion. Hence cordgrass was planted at coastal sites throughout the British Isles, and in Asia, Australia, New Zealand, and North America.
New colonies take time to become established, but once ensconced, their rapid vegetative spread smothers competitors and even prevents wading birds from feeding. The introduction of common cordgrass invariably caused extensive damage to natural saltmarsh ecosystems.