330 NOTES OF A BOTANIST 



river. I propose here to treat of the lower part of these two rivers, 

 and especially of the Chira, in some detail. 



The configuration of the coast-region from Cape Blanco to and 

 beyond the Piura is as follows : On the western margin rise steep 

 cliffs to a height of from 200 to 300 feet, either directly from the 

 sea or with an intervening beach uncovered at low-water, and 

 usually with a low reef of rocks at about half-tide, whereon even 

 the gentle waves of the Pacific break in a dangerous surf. Having 

 surmounted the cliff, we are on what is called the tablazo, a 

 plateau rising very gently to eastward, in some places slightly 

 undulated, and in others with ridges of considerable height rising- 

 out of it, the whole so bare of vegetation that there are places 

 where not a single tree, much less an herb, can be distinguished 

 within the limits of vision. A bold abrupt ridge, called the Silla 

 de Payta, rises immediately to southward of that town to a height 

 (according to Captain Kellett) of 1300 feet; but a far more 

 important range of hills, beginning from near the sea, a little to 

 northward of the mouth of the Chira, runs with a direction of 

 E.N.E. all the way up between the rivers Chira and Tumbez, till 

 it mingles with the Andes towards the sources of the latter 

 river. ... I suppose these hills to rise, even in their western 

 part (which is all I have seen of them), to from 2000 to 3000 

 feet; to eastward, as they near the Andes, they must be far 

 higher. Viewed from the south, they appear entirely bare of 

 vegetation, but when they come to be examined their deep 

 ravines are found to contain a few scattered Cactuses, Algarrobos, 

 and other trees ; and I am told that on their northern slope there 

 is considerably more permanent vegetation, much as on the hills 

 of Chanduy and St. Elena, which, although of far less extent, 

 have quite the same aspect and structure. 



The country to southward of the river Piura is known as the 

 Despoblado (or Desert) of Sechura : but in reality that term might 

 be extended to the whole desert region which stretches northward 

 to the skirts of the forests of the Gulf of Guayaquil, for the narrow 

 strip of vegetation along the courses of the Chira and Piura are 

 mere oases in that vast desert. 



The deep valley along which the Chira flows to the sea has 

 plainly been excavated by the action of water, and if any 

 depression have originally existed on the tablazo along the same 

 line it must have been very slight, as there is now no appreciable 

 sloping towards it. Its sides are steep cliffs, scarcely at all 

 furrowed transversely on the southern side, but on the northern 

 side in most places very much broken up into ravines and 

 alternating peaked ridges, whose origin may be traced to the 

 effect of the rare but torrential rains descending the rugged slopes 



