buffel grass
Cenchrus cillaris
  a native of southern Asia and east Africa, buffel grass was introduced to Australia as an excellent fodder that can withstand heavy grazing, but its displacement of native grass is now a major concern, particularly in the arid inland of Australia where it forms dense swards in moist habitats such as along river banks or in alluvial pans  
  Serpentine Gorge, West MacDonnell National Park - 16th July 2006