﻿74 



SMITIiSON lAX M ISCEI.I.AN EOUS COLLECTIONS 



\'OL. 



74 



required the use of artiticial heat, the [jlants being put between driers 

 and corrugated Ixjards, bound tightly in packages, and ])laced over a 

 charcoal-burning heater. 



As might be expected from its physiography, the vegetation of 

 Colombia is extremely diverse. \\^ithin a few miles mav occur a 

 luxuriant tropical flora, the more open woods of the temperate zone, 

 and the low alpine growth familiar on our American mountain tops. 

 Again, as in the Dagua Valley, one may ride through a dense rain- 

 forest, filled with ferns, mosses, and aroids, to emerge suddenly in 

 an arid, desert-like region where cacti and acacias are the conspicuous 

 plants. 



Fig. 74. — Crest of tlie Western Cordillera at EI Derrunibo, 9,500 feet alti- 

 tude, Colombia. Here occurs the stunted growth of the temperate zone. 



Since Colombia lies between the first and eleventh parallels, the 

 development of its vegetation is little influenced by latitude. The 

 controlling factors are altitude and precipitation, the rainfall ranging 

 from 400 inches a year to almost perpetual dryness. Four zones of 

 plant life may be recognized, the limits being approximately as 

 follows: Tropical, from sea-level to 5.000 feet; Stibtropical. from 

 5.000 to 9,000 feet; Temperate, from y,ooo to 12,000 feet; Paramo, 

 above 12.000 feet. The tr()])ical forests are very dense; giant-leaved 

 aroids, bromeliads. and heliconias are most abundant ; everywhere are 

 palms and bamboos. In the subtropical forests orchids become more 

 common, many of them being of great beauty ; tree trunks are densely 



