Between Alisma and Ludwigia, which genus is spread more widely around the world?
Alisma: Alisma is a genus of flowering plants in the family Alismataceae, members of which are commonly known as water-plantains. Ludwigia (plant): Ludwigia (primrose-willow, water-purslane, or water-primrose) is a genus of about 82 species of aquatic plants with a cosmopolitan but mainly tropical distribution.
i don't know