Paspalum distichum
 Paspalum distichum is a species of grass known by the common name knotgrass. Other common names include couch paspalum eternity grass gingergrass and Thompson grass. Its native range is obscure because it has long been present on most continents and in most areas it is certainly an introduced species. Its native range probably includes parts of the tropical Americas. This is a perennial grass forming clumps and spreading via rhizomes and stolons.