Li Lg. T owe. 
BOTANICAL EXCURSION TO SALINAS. 381 
May, and corresponds to the wet season of the coast. The 
western ridge of the Andes, of which Chimborazo forms the 
loftiest summit, presents a barrier intercepting the clouds 
and condensing them in showers of rain, while the climate of 
the eastern side is characterized by the opposite extreme. 
Notwithstanding the bad weather, I added to my collection 
Polylepis lanuginosa (No. 204), which of all trees is perhaps 
that which grows at the greatest elevation on the globe. The 
trunk, nearly destitute of bark, is gnarled and twisted in the 
most fanciful manner, and the root penetrates deeply the 
rocky crevices, thus enabling the trees to resist the violent 
winds with which they are assailed during the period of the 
dry season. Between the limits of 1300 and 1400 feet they 
constitute a well defined zone characterized by the absence of 
all other trees. The more remarkable plants occurring in 
the same region are Gentiana cernua, (No. 184), Calceolaria, 
(No. 178), Eryngium humile, (No. 159), Silene, (No. 39), 
Baccharis thyoides, (No. 98), and Lathyrus, (No. 44). Lower 
_ down, these plants give place to the grasses, and at 1200 feet 
we again observe patches of forest; not of Polylepis, but of 
Aristotelia Maqui and Columellia sericea, (No. 58). "There is 
not, as in the central Cordillera, a well defined zone of 
shrubs. They may be equally numerous, but they are inter- 
mingled with forest trees. "l'here are no pines, and oaks are 
very rarely found. The plants that abound most are arborescent 
and shrubby Composite, No. 188, 245), Rosacee, (No. 223, 
224, 225), Melastomaceæ, (No. 169, 230), Scrophularinee, 
= (No. 178, 180, 181, 182), and Loranthee, (No. 224). The 
. Same observation respecting shrubbery is applicable to the 
.. descent of the Cordillera towards the source of the Marañon 
With this peculiarity, that the lofty ridge of the eastern chain 
. Produces, in the greatest abundance and of the most luxuriant 
3 Browth, a tall gramineous plant, (No. 92), impenetrable to 
. Wn or horse, and consequently any investigation in that 
.. Quarter is attended with serious difficulties. ; 
: The constant rain of the preceding months had rendered 
-: he road extremely bad.. I had calculated on reaching Gua- 
