Which genus has more species, Fontanesia or Antigonon?
Fontanesia: Fontanesia is a genus of flowering plants in the family Oleaceae, usually treated as comprising a single species Fontanesia phillyreoides, though some authors split this into two species (see below). Antigonon: Antigonon is a genus of flowering plants in the buckwheat family, Polygonaceae. Antigonon:  It contains three species native to the Americas.
Antigonon