English: Mosses mostly grows on the north side of the trees , simple plant and likes to grow in shady locations so it does not dry out, the reason is that in the northern hemisphere, because of the tilt of the Earth on its axis, the sun almost always appears to be a little south of directly overhead , that's why rooms with windows facing south are brighter than rooms with windows facing north , this is important for the mosses because the north sides of trees (in the northern hemisphere)are shadier and therefore moister , the south sides of trees get more sunlight, so water evaporates faster there.

English: Mosses on the trees