Note 25 — STEPPES AND DESERTS.

p. 12.—“Neither Lecideas nor other Lichens.”

In northern countries, the earth, if left bare, soon becomes covered with Bæomyces roseus, Cenomyce rangiferinus, Lecidea muscorum, L. icmadophila, and similar Cryptogameæ, which prepare the way for the growth of grasses and herbaceous plants. In the tropics, where mosses and lichens only abound in shady places, some species of succulent plants take their place.