188 RELATION BETWEEN CLIMATE AND VEGETATION 



Further on I gathered a magnificent species of Tacsonia with 

 pink flowers. 



Upon the crest of the Cordillera begins the province of Ayo- 

 paya ; every part of it which I visited is above the limits of 

 the high forest vegetation. As far as Morochata in particular, 

 the steep face of the mountain on which the road runs, presents 

 nothing to the eye except a little alpine grass, or the bare 

 surface of the sandstone or schistous rocks of which it is com- 

 posed. The miserable inhabitants of this canton cultivate 

 nothing but Barley and Potatoes ; but round Palca, the capital 

 of the province, there are fields of corn and even Maize, and at 

 the same height a great number of shrubs, especially of spiny 

 Mimosas. 



From Palca I went to Ynquisivi, the chief town of the province 

 of the same name. As I advanced vegetation became more 

 abundant and more diversified ; every step I took brought me 

 neai'er a tropical climate ; but the descent is so gradual that the 

 limits occupied by the different plants are not nearly so well 

 marked as in other places I have seen. The Cactus is very 

 abundant here, and either alone or in company with Mimosas 

 forms large forests. When descending towards the bed of the 

 llio Ayopaya, I remarked on one of these succulent plants a 

 leafless Loranth of a brick-red colour. From the river last 

 mentioned the road passes into the bed of the Rio Cato, which 

 has to be followed upwards for several leagues before the beau- 

 tiful village of Ynquisivi can be reached. This place is on a 

 verdant platform halfway up a very steep mountain, at the foot 

 of which is a roaring torrent. 



The interminable zigzag of the roads in these countries 

 renders it difficult to ascertain, without actual measurement, the 

 amount of its general slope. Without however knowing this, 

 the changes of temperature in each new place showed me 

 that I was gradually approaching the domains of tropical nature. 

 I found, indeed, near fSuri, 7 leagues from Ynquisivi, Plantains 

 and Cecropias, then, a little lower, Cinchonas, then Palms and 

 Arborescent Ferns which I had not seen for a very long time. 

 The parts of these mountains v^hich are most exposed to the 

 south have been long since cleared of their forests and planted 

 with Coca,* which I saw here for the first time alive : its im- 



* The Coca {Erythroxylon coca) is a bushy shrub 1^ foot to 2 feet in 

 height, with pale-green leaves, small, simple, and marked with three longi- 

 tudinal nerves ; its flowers are white, with very little scent ; its fruit is a 

 drupe, at first green, and then intensely red. 



As a horizontal piece of ground of any extent is unknown in the countries 

 where the coca is grown, it is always found on the sloping sides of the 

 mountains, and exposed as much as possible to the rays of the sun. To 



