TERTIARY FLORA OF CHILE 77 



plateaus sloping gradually seaward and partially bounded 

 along the coast by the low coast range from which the 

 descent beneath the waters of the Pacific is rapid. 



This region is rainless and consequently barren and with- 

 out vegetation except in the region of melted snow of los 

 Andes and in some small river valleys where irrigation is 

 possible. At Coquimbo the mean annual temperature is 

 59.2 F. and the rainfall i l / 2 inches. Central Chile, or the 

 region from Coquimbo to Llanquihue, shows but a slight 

 lowering of temperature and a gradual increase in rainfall 

 as one proceeds southward. Hence it constitutes a rich agri- 

 cultural country and supports a varied vegetation. Most of 

 the peculiar genera of temperate South American plants 

 belong to this province. 



Southern Chile not only exhibits a striking contrast to the 

 northern desert region but an almost equally sharp contrast to 

 the corresponding latitudes in Argentina on the other side 

 of the Andes, resulting from the combination of prevailingly 

 westerly winds and high mountains. In the absence of the 

 latter the climate of both would be similar. 



South of the Rio Bio Bio the rain forest flora gradually re- 

 places that of the central region. Its most prominent ele- 

 ments are the Chilean pine (Araucaria imbricata) and the 

 evergreen beech (Nothofagus). 



Peculiar elements are the Alerce (Fitsroya), the Chiloe 

 and Chilean cypress (Libocedrus and the winters bark 

 (Drimys) all relics of earlier geological periods. 6 



The only meteorological records for the region from which 

 the fossil plants come are in the admirable series published 



8 Neger, F. W., Die Vegetations verhaltnisse im nordlichen Arau- 

 carien (Flnssgebiet des Rio Bio Bio) Engler's Jahrbiicher, Bd. 23, 

 1806. 



Skottsberg, C. V., Die Vegetations verhaltnisse langs der Cordillera 

 de los Andes S. von 41 S. Br. : Ein Beitrag zur Kenntnis der Vege- 

 tation in Chiloe, West-Patagonien, den Andinen, Patagonien und 

 Feuerland. Bot. Ergeb. Schwed. Exped. nach Patagonien und dem 

 Feuerlande 1907-1909. 366 pp. Stockholm, 1916. 



