CHAP, xvi RESIDENCE AT TARAPOTO 



99 



The ridges and peaks are of white sandstone, as 

 are those of the Andarra farther up the river. 

 Both are very bare of vegetation, being burnt 

 almost every year and overrun with the common 

 fern Pteris caudata. The ascent to Potrela up the 

 rocky valley of the Cuchi-yacu is, however, through 

 luxuriant forest especially rich in ferns and mosses. 



To conclude this sketch of the Tarapoto district 

 investigated by Spruce, I will give a few passages 

 translated from his "Precis d'un Voyage" pub- 

 lished in the Revue Bryologique for 1886 : 



" The first thing that strikes the eye of the 

 botanist at Tarapoto is the abundance of ferns. 

 These plants are by preference, as we know, either 

 maritime or subalpine. On the hills of Brazil a 

 tolerably large number of species are found, but in 

 the interior of the continent and in the great plain 

 of the Amazon valley, although ferns are not 

 wanting, yet the species are never numerous and 

 several of them repeat themselves at every step 

 even up to the roots of the Andes. One may 

 therefore judge of the riches of the Eastern 

 Cordillera of Peru in ferns by the fact that there, 

 within a circle less than fifty miles in diameter, 

 the author found 250 species of ferns 

 allies, of which many were new, especiall 

 the tree-ferns." 



Among the most interesting plants in this 

 region, next to the ferns, may 

 Rubiace:e, of which Spruce collected 98 specie 

 small number of these were already known throu 

 the researches of Ruiz and Pavon, Poeppig 

 Matthews, but the majority 

 " Precis " then continues : 



