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the Arroyo del Medio and Rio Guayabo, tributaries of the lower 
Mayari. Farther westward is Rio Guava, which flows across the 
coastal plain into Nipe Bay. On the east side of the plateau are 
the Rio Seco, Rio Naranja and Rio Piloto, tributaries of the 
upper Mayari. These rivers usually have their source in many 
small tributaries which spring from deciduous woods or thickets, 
and flow over rocky beds entirely devoid of sand, mud or fishes, 
cutting deeper and deeper as they attain volume. The sparkling 
clear water, free from mineral substances and said to be almost 
chemically pure, bounds over boulders and precipices in a con- 
tinuous chain of rapids and cataracts, and finally takes an im- 
he richest collecting in this region was along these streams. 
The Arroyo del Medio and the largest of its tributaries, the 
“Sawmill” Arroyo, were systematically worked from the big falls 
upward to their sources; most of their branches were also simi- 
larly explored. Rio Guayabo was touched at the falls and at 
several points above, but heavy rains prevented extensive ex- 
plorations on this stream. 
The foothills were worked principally by way of the Piedra 
Gorda-Woodfred trail. This trail is about five miles long and 
was opened up by the iron company only a few years ago, pre- 
liminary to its operations in the region. Being new and its 
margins comparatively free from the ravages of fires, so frequent 
in this section, one gets into the heart of the scrub and can work 
in and out on either side. The advantage of being able to return 
in the dark. It was along this trail that most of the species 
peculiar to the foothills were obtained. The Bandera trail, con- 
necting Mayari and San Luis, passes several miles to the west- 
ward of Woodfred, but being an old Spanish trail and its margins 
badly fire-swept, it afforded no good collecting. It was probably 
on this trail that Charles Wright secured the plants peculiar 
