Plant geographers have used a number of techniques for making plant maps. For recording general distributions, outline plant maps are really only appropriate on small-scale continental or world maps where a more thorough and accurate method is neither possible nor necessary. Ross Mackay has developed a useful nomograph to assist in determining the most satisfactory dot size and density, and many plant. Geographers would do well to use such an aid in the preparation of their dot maps. This nomograph requires knowledge of the sizes of dots that can be made with various types of pen. Like any other map, the success of a plant map will depend to a considerable extent on the choice of a suitable map projection. For mapping distributions in polar region, Lambert’s Polar Zenithal Equal-area projection is possibly the most useful, although for the tropics any equal-area or general world projection which shows the hot areas well would be appropriate.