Moth plant is putting on an autumn growth spurt but these flowers are a bit late - spring-summer, summer, summer-autumn flowering, depending on what you read.
I didn't see any sign of treatment. Perhaps @ACTBioSecurity was misled by the trampling and cut log where it looks as though someone has been stealing firewood. I have now stem-scraped and poisoned the plant and recorded it on Field Maps. The main stem was about 5 metres long.
My apologise @Mike. There was another moth plant sighting reported at the same time as this one, and I have accidently commented on this one and not the other. Thank you for treating it. @ACTBioSecurity have been working on known moth plant sights the last couple of days and will be working down in that area today, so we can have a hunt around to see if there is any more in the area. Thankyou