Chap. Ill] MOUNTAIN REGIONS IN THE TROPICS 



743 



the alpine climate is most clearly stamped on the vegetation, especially in the higher 

 part of the region, with its dwarf plants. Protective measures against transpiration 

 are everywhere strongly developed, in particular dense coatings of woolly hairs 

 are frequent. 



4. THE REGIONS IN TROPICAL AMERICA. 



i. THE SOUTH AMERICAN CORDILLERAS. 



Of the equatorial Cordilleras in New Grenada, Ecuador, and Venezuela, 

 the basal and montane regions have very moist climates, so that they 

 are both clad with rain-forest, which 

 is tropical in the basal region, 

 and temperate in the montane. The 

 temperate rain-forest is the home 

 of most cinchonas. The alpine 

 region commences with elfin-wood 

 and shrub- wood, but uptothe limit of 

 perpetual snow consists essentially 

 of steppes, termed paramos, which 

 are sometimes treeless, but at other 

 times bear isolated, gnarled dwarf- 

 trees (Polylepis lanuginosa, H. B. 

 Kth., on Chimborazo). Further to 

 the south, in Peru and Bolivia, forest 

 is confined to the rainy eastern 

 slopes, whilst the western slopes 

 are covered by desert and semi- 

 desert. Here, the very extensive 

 alpine region, the puna, has a desert 

 character throughout (Fig. 439). 



On the paramo-steppe, between 

 narrow-leaved grasses and low 

 herbaceous perennials, there stand 

 highly peculiar, tall Compositae, 

 which have received from the natives 

 the general name 'frailejon,' although 

 they belong to numerous species of two genera, Espeletia and Culcitium. 

 Their ensiform, densely hairy leaves, as long as one's arm, form rosettes, 

 which are sometimes pressed to the ground, and sometimes crown a massive 

 stem clad in a mail of the dead leaf-bases. 



In passing from the paramo, which is moistened by frequent rains and 

 mists, to the dry puna, tall plants of this kind completely disappear. The 

 landscape is chiefly dominated by a grass, Stipa Jehu. ' These tufts of 

 grass are responsible for the peculiar character of the vegetation of the 



Fig. 440. Alpine flora of the Cordilleras. Lori- 

 caria ferruginea.Wedd. (Compositae. At the level 

 of perpetual snow. New Grenada and Ecuador. 

 After Weddell. 



