NATURAL AREAS AND REGIONS 



631 



considerable narrow forests, which have 

 been best described for the lower course 

 of the Rio Meta. Such river-forest 

 includes large trees of Bombax and 

 Ficus, and contrasts with other lowland 

 forests in its considerable number of 

 epiphytes, bromeliads, orchids, etc. 



"The mammals are not well known, 

 but include the savanna white-tailed 

 deer (Odocoileus), brocket deer (Ma- 

 zama), puma, jaguar, ocelot, tayra, 

 armadillos, and anteaters. The large 

 deer (Odocoileus) is of northern affini- 

 ties and does not extend to the central 

 Amazonian region as do most of the 

 other mammals." 



On the Llanos of Casanare rainfall 

 is seasonal, a wet season lasting from 

 April to October, and a strongly marked 

 dry season from December to March. 



The "Llanos" are being increasingly 

 grazed, and it may not be many years 

 before this magnificient pasture-land 

 follows the history of the prairies of 

 the Mississippi Valley and the Pampas 

 of Argentina. It is practically un- 

 touched by the plow. 



The Llanos may be studied on the 

 plains of the Meta east of Villavicencio, 

 reached by trail (5 days) over the 

 Eastern Cordillera from Bogotd,. Vil- 

 lavicencio, just at the foot of the cordil- 

 lera, is in the San Martin type of mixed 

 country, with interspersed belts of 

 forest and prairie. A trail runs south- 

 ward to the town of San Martin. In 

 order to see the true Llanos of Casanare 

 one should visit some of the plains 

 settlements to be reached by trail over 

 the cordillera from Tunja in Boyaca, 

 a town now accessible by automobile 

 from Bogota. The country near the 

 lower Rio Meta, both river-forest and 

 prairie, may be reached by boat from 

 Ciudad Bolivar on the Orinoco in 

 Venezuela to Orocue, Colombia. 



4. Llanos of the upper Magdalena 

 Valley. South from Honda and Mariqui- 

 tain Tolima the floor of the Magdalena 

 Valley and the lower mountain-slopes 

 to the sides are devoid of evergreen 

 forest, being covered either where flat 

 or rolling or on the exposed foothills 



with grasses and herbs, or on gorge and 

 canyon sides or in the foothill valleys 

 with brushy thickets and xerophytic 

 forest. The chief open grasslands are 

 in the three small plains, the "Llanuras" 

 of Mariquita and of Purificaci6n in 

 Tolima and the "Llanura" of Neiva in 

 Huila. These prairies are essentially 

 similar to the other lowland llanos of 

 Colombia, but compared with the Llanos 

 of Casanare have a restricted variety 

 of component plants. Andropogon and 

 Bouteloua are characteristic grasses, 

 while Bradburya, Meibomia, Polygala, 

 Sida, Eriosema and Buchnera are fami- 

 liar herbs. The thickets and low forest 

 become more xerophytic south- 

 ward, the large species of Cact- 

 aceae being increasingly conspicuous. 

 River-banks are lined by groves of 

 palms and growths of bamboos. 



"The mammals are generally similar 

 to those of the Caribbean Llanos, 

 those of some groups being differentiated 

 into peculiar subspecies or geographic 

 representatives." 



The upper Magdalena Valley has 

 two wet and two dry seasons, the wet 

 seasons being from April to June and 

 from October to December. 



The "Llanuras" or prairie portions 

 of the Llanos of the upper Magdalena 

 Valley are extensively grazed, but they 

 have been only locally altered in char- 

 acter by the introduction of foreign 

 grasses or by being broken for agricul- 

 tural purposes. 



The prairie portions may be readily 

 visited at Mariquita and San Lorenzo 

 in Tolima along the railroad from La 

 Dorada to Ambalema, and with more 

 effort at Natagaima in Tolima and 

 Neiva in Huila, towns reached by trail 

 south from Girardot. The hilly portion 

 of the upper Magdalena Valley may be 

 observed at Honda in Tolima, Girardot 

 in Cundinamarca, and shortly above 

 Natagaima. 



5. Llanos of the Cauca Valley. The 

 Cauca Valley from western Antioquia 

 southward, and continuous therewith 

 the Patia Valley, constitutes an unfor- 

 ested open or brush-covered lowland 



