Native grass or is it?

Native-grass? Or is it an exotic weed? This little plant sprung into life after the recent flood in the gorge. It looks a little bit like South African weed that is wide spread in W.A. Any ideas anyone?

Native-grass? Or is it an exotic weed? This little plant sprung into life after the recent flood in the gorge. It looks a little bit like South African weed that is wide spread in W.A. Any ideas anyone?