A heavy falciparum parasitaemia: rings in a large fraction of red cells, some cells carrying two or three. Multiple infection of one cell is itself a falciparum clue.Dr Graham Beards, via Wikimedia Commons · CC BY-SA 4.0 · sourceA peripheral blood smear field: red cells with central pallor and one segmented neutrophil.BCCD blood cell dataset (Shenggan) · MIT · sourceThe banana: crescent-shaped gametocytes are specific to Plasmodium falciparum. They are the sexual stage, do not cause disease, and can persist after treatment.CDC Public Health Image Library · Public domain · sourceA smear field: red cells around a mononuclear leukocyte.BCCD blood cell dataset (Shenggan) · MIT · source