p 6 t e I s i a 57 



At the higher elevations along the base of 

 rocky ledges and in large crevices where there is 

 enough soil to yield a foothold, the plants oc- 

 curing most frequently are: 



Poly podium falcatuni AcJilys triphylla 



Asplenium trichoma 11 es Tiarella trijoliata 

 Berheris nervosa Trientalis latijolia 



Mosses and lichens occur in considerable 

 quantities upon the rocky ledges and shelves. 



San Juan A^allcv. The vegetation of the two 

 valleys differs only in smaller details. This finds 

 its explanation in the slope and trend of the 

 valley and in the nature of the soil. The fall 

 of the river in the same distance is not as great 

 as that of the Gordon and one finds often along 

 the banks small grassy meadows and forest open- 

 ings, especially in the lower portions where there 

 is considerable alluvial deposit. Farther up the 

 valley are frequent evidences of moraines and 

 although the surface soil is made up of decaying 

 vegetation as everywhere else in the region, the 

 subsoil is a moraine deposit and dissimilar con- 

 ditions are therefore experienced. 



The direction of the harbor and the valley 



