Crassocephalum.
Family Asteraceae > Subfamily Asteroideae > Tribe Senecioneae.
Plants of the World Online accepts 25 species of Thickhead, Fireweed or Redflower ragleaf.
Native to Africa and Madagascar Australia has one 1 naturalised species, Crassocephalum crepidioides
which is common in south-eastern Queensland.
They look like thistles but have no prickles.
The flower heads are discoid having only disk florets and no ray florets.
J.F.