Chap. Ill] MOUNTAIN REGIONS IN THE TROPICS 



739 



branches are completely overhung with lichens, particularly Usnea barbata. They 

 belong to a few species only: Agauria salicifolia, Erica arborea, Ericinella Mannii, 



in the north also Gnidia Volkensii. Occasionally the Erica forms small groves, in 

 the shade of which a hygrophilous vegetation develops. 



3 B 2 



