Which genus contains more species, Prosopis or Aldrovanda?
Prosopis: Prosopis is a genus of flowering plants in the pea family, Fabaceae. Prosopis:  It contains around 45 species of spiny trees and shrubs found in subtropical and tropical regions of the Americas, Africa, Western Asia, and South Asia. Aldrovanda: Aldrovanda is a genus of carnivorous plants encompassing one extant species ("Aldrovanda vesiculosa", the waterwheel plant) and numerous extinct taxa.
Prosopis