Echinochloa polystachya

Echinochloa polystachya, the German grass, is a species of grass (family Poaceae), native to the New World Tropics and Subtropics, from Texas and Florida down to Argentina. It is an aquatic or semi-aquatic perennial that can grow in water as deep as 2 m (7 ft). It is a useful fodder for water buffaloes, and to a lesser extent, cattle. In the Amazon floodplain it can reach productivity levels of 99.6 t/ha (39.7 long ton/acre; 44.4 short ton/acre) in dry mass, one of the highest levels ever measured in natural vegetation and belongs to the C4 plants . Given that it occupies about 200,000 km2 (77,000 sq mi) of territory during the rainy season, it contributes on the order of 1% of the primary productivity of the planet....read more on Wikipedia.