Sorry, I should have written stalks, but these are not in the Plantnet description or Papaver key. I will wait for some capsules to mature as these give a good clue.
I have been to this area again. Apart from a couple of little opium poppies https://canberra.naturemapr.org/Community/Sightings/Details/3870334 all the others have elongated smooth capsules. Despite the fact they commonly have black at the base of the petals they are Papaver dubium.