Ho chiesto direttamente in loco, e questa è stata la risposta:
Buongiorno Vladimiro, Thank you for your enquiry. The plant in your photos is: Typha domingensis. This is a native species to Simpsons Gap & is using the water that is underground and fed by a small spring. Here is the NT flora link for a little bit more information, and pictures of when the plant is in a happier state.
Link I am sure you enjoyed the very warm weather but it is such a shame it was so dry during your visit and with very few plants flowering in the region. Regards Peter
Peter Jobson Senior Botanist Northern Territory Herbarium, Alice Springs Department of Environment & Natural Resources PO Box 2252 Alice Springs NT 0870 P: 08 895 18791