Echinochloa crus-pavonis (gulf cockspur grass).
Echinochloa crus-pavonis is a clump forming grass native to the Americas that is now found in Africa, Asia, Oceania and Europe. It is likely its spread was facilitated by rice cultivation around the world, as it is a frequent contaminant of rice grains. It listed as invasive and a weed of agriculture. E. crus-pavonis is widely documented as a significant weed of rice fields. It is an 'occasional weed of cultivation' in Australia. It is considered invasive in Cuba, Paraguay, Cameroon, the Ivory Coast, Nigeria, Italy and California, USA.