In theory, the concept of peculiarity or restriction to one limited region can be applied at any scale, whether it is the distribution of weeds on a single patch of lawn, of mosses between two bricks in a wall or of a taxon with a very narrow distribution when viewed from the world scale. In practice, however, such an all-embracing approach is of limited value and in plant geography at least the concept needs further qualification. The classification of endemic distribution types is complex, and its history and terminology have been reviewed by C. Favarger and J. Contandriopoulos, H. C. Prentice, I. B. K. Richardson and G. L. Stebbins and Major. In general terms, the number of endemics in the northern hemisphere is lower than that in the southern hemisphere, although in both hemispheres their count is particularly reduced in the lands which were occupied during the Pleistocene by the cap of the continental glacier.