Roadside flowers

Seen near the roadside in western Queensland. I had thought this to be an Australian native plant I could not identify, and had posted to that effect, but Nora Caracci (see below) has now correctly identified it as an import from Madagascar. What's more, it has reached the status of being an invasive weed! Since taking this image, I have also found and photographed it (see note) in another area much closer to home.