CH. xxxii THE WEST COAST OF SOUTH AMERICA 475 



the character of the beach-flora from the appearance of the land 

 behind. In the Gulf of Guayaquil and in the vicinity of the city of 

 that name I spent about three weeks in the investigation of the 

 coast flora. 



If it were not for the interposition of the great rainless deserts 

 of Northern Chile and for the scantily vegetated, scantily watered 

 and semi-sterile condition of almost the whole coast of Peru, the 

 botanist would be presented with a splendid opportunity of study- 

 ing the distribution of shore-plants along a meridian stretching 

 through some fifty degrees of latitude from Patagonia to Ecuador. 

 As it is, drought and sterility in one form and another reign 

 over about half of this great stretch of continental coast. This 

 is reflected in the beach-flora ; and though the observer will 

 often have his interest attracted by the wonderful climatic 

 anomalies arising from the presence on the coast of the cold 

 Humboldt current, to which the sea-border of North Chile owes 

 its desolation and the coast of Peru its semi-sterility, yet for a 

 long time he will feel as if Nature had hardly dealt fairly with 

 him. 



Along the sea-border corresponding to the deserts of North 

 Chile there would seem to be practically no plants growing on the 

 beaches, except here and there where some stray plant from the 

 saline districts inland intrudes on the coast. Along the whole 

 sea-border of Peru from Arica north to Tumbez on the borders of 

 Ecuador, the coast-districts, though more or less rainless, receive 

 the benefit of the drizzly garuas and sea-fogs, and the sterility of 

 the land immediately backing the beaches is much less pronounced 

 than with the sea-border corresponding to the deserts of Northern 

 Chile. This difference shows itself in a peculiar type of littoral 

 vegetation, a strand-flora that is very scanty but one where on the 

 beaches Sesuvium prevails. North of Tumbez the mangrove- 

 formation predominates along the sea-borders of Ecuador and 

 Colombia to Panama, excepting on a stretch of sterile coast 

 extending north from the Gulf of Guayaquil to the equator. 



Though in one sense the botanical observer will be disap- 

 pointed with the littoral floras of the west coast of South America^ 

 in another sense when he remarks the manner in which the coast- 

 vegetation reflects the abrupt changes in the prevailing climatic 

 conditions he will be fascinated by the interesting problems pre- 

 sented to him. We are accustomed to connect a tropical coast 

 with mangroves, coral-reefs, and beaches of calcareous sand sup- 

 porting a luxuriant littoral flora. Climatic conditions banish all 



