Dot Distribution Map

Each dot indicates an area of duckweed occurrence.
Legend for numbers: The occurrence of Lemnaceae lacking due to: 1 = too dry, 2 = too wet, 3 = too cold, 5 = not sufficiently explored

http://www.mobot.org/jwcross/duckweed/Lemna_graphics/Map2.gif
Dot distribution maps use dots top show incidents. This particular map is used to show the presence of Duckweed across the world. This number also cooresponds to a legend displayed at the bottom, indicating the type of environment.