Moss Growing on Big Stones
If you look very closely at this National Geographic Photo of the Day you will see a very fine dusting of moss growing on these rather unusual natural stone formations.
(Photograph by Jodi Cobb, for National Geographic magazine)
See to the left there, there’s some Sphagnopsida and just below that is a fine example of a Andreaeobryopsida.
What’s most remarkable is that there are no cacti growing along the sides of this particular stone outcropping. Normally, one would find a healthy growth of cactus alongside moss growing on stone formations.
from wikipedia