Myriophyllum aquaticum
Emerged leaves all with fine linear lobes to the midrib, narrow-elliptic in outline, up to 25 mm long; submerged leaves more finely dissected. Bracteoles linear, divided. Mericarps not produced in Aust. Coast and Cumberland Plain. Still water. Introd. from S. America. Possum Tail or Parrot’s Feather