03:14 · In botany, ideograms are needed to denote where on earth different plants have their habitats. The sign used for this purpose is that meaning fixed star, , a common symbol for orientation by the fact that the fixed stars were the main points for taking one's bearings on long sea voyages in the antiquity.
    By adding a straight line above, below, or on one of its sides, the different parts of the earth can be represented. The graph here shown denotes the old world, the eastern hemisphere, i.e. Eurasia.