that area has a lot of non-native species, and it would be a major weeding exercise to reduce the shoreline area to just native species. I left it: its non-invasive. This is an end-of-season species. It gets noticed because it is so tall, but not if cattle are present. It is habitat restricted, favouring a drying habitat. Combination of soil conditions and season requirements mean it may not always be present.
OK, I realise it is a weedy area, and I have not seen this species often. And where I did see it on Mount Majura it was about this time of year and not near a shoreline, but it was a much wetter season. Thanks for explaining its modus operandi. Barbara