Very nice reflections Steve. They almost look like our Cattail plants
Typha gracilis. They grow in areas of very soggy soil around ponds and swampy areas. It looks like your cumbungi can grow in a little deeper water than the cattails. Both plants have eatable parts and were used by indigenous people on both our continents. I found this little link you might like.
http://home.vtown.com.au/~dbellamy/native/cumbungi.html
Lifebuoys, the Titanic and one hell of a weed problem
The reason for the importation of the weed Typha latifolia into Tasmania, relates to the concern by the general populous that boating and swimming could be made safer by supplying ample lifebuoys etc in boats and at swimming venues. This concern was exacerbated by the news of the huge numbers of drowning, associated with the sinking of the Titanic.
The light fluffy "kapok" like seed heads of the cumbungi was ideal for compressing into floats and other buoyancy devices such as lifebuoys. To ensure ample raw material the weed species of cumbungi was introduced from Europe and that initiated the weed problem of today.
"It seems like nature is balanced until we get into the equation"
"Thank you for making me look up info on something I would have never known about"

Take Nothing but Pictures--Leave Nothing but Footprints.
Doug Breda