84 JOURNAL OF FORESTRY 



water-shed, especially on the slopes of the Chiriqui volcano, a gradual 

 change is observed during the ascent, a group of families after another 

 showing its predominance. At an altitude little above i,ooom., in the 

 Boquete Valley, Ulmus mexicana, Cedrela, Sapium, and Inga species 

 are very common, but the Lauraceas become more and more frequent 

 with the progress toward the summit until some of its representatives 

 form a real gregarious forest up to an altitude of about 2,500 m. 

 Above this the evergreen oaks, which appear first in isolated clumps 

 at a much lower altitude, form extensive groves up to the upper timber- 

 line. The underbrush is never very heavy at high altitudes and strongly 

 mixed with annual or suffruticose plants. Several epiphytes become 

 terrestrial, and a nettle, Urtica irazuensis, forms in places extensive 

 fields under the shade of the oaks. On the whole, the vegetation 

 assumes here a subtropical or even more northern character. Toward 

 the upper forest line, in the cool vales around the upper peak, there are 

 clumps of forest almost exclusively formed of large, but stunted and 

 spreading Escallonia, which I consider to be the E. posana of the Costa 

 Rican Mountains. 



