Wildlife Spotting

The edges of the New England Highway around Tenterfield were thick with thousands of these flowers when I took this shot a month ago. I wanted to get a wide shot of a bunch of them together, but unfortunately there was nowhere safe to pull over in the thickest patches! The stems were up to a metre tall and the flowers themselves were over 10cm long. I suspect they are some kind of weed but I'm not sure. I drove this route again last week and they were nearly all gone.