THE VERBENA FAMILY. 201 



slopes, at this season almost completely bare of 

 vegetation, and I decided on following the valley of 

 the Rio Colorado, where, at least along the banks 

 of the stream, vegetation was comparatively abundant. 

 My obliging host had provided a horse and a guide, 

 and I rode for about an hour up the valley, which in 

 great part is narrowed nearly to a ravine. In one 

 place, where it widens to a few hundred yards, I 

 passed a peasant's cottage, with a few stony fields 

 from which the crop had been gathered. 



Among the plants not before observed, I was at 

 first puzzled by a sort of thicket of long green leafless 

 stems eight or ten feet in height, growing near the 

 stream. Only after searching for some time I detected 

 some withered remains of a short spike of flowers at 

 the ends of the stems, which showed the plant to be 

 of the Verbena family. Whatever may be the original 

 home of that ancient tribe which has spread through- 

 out all the temperate and tropical regions of the 

 earth, it is in South America, and especially in the 

 extra-tropical regions, that it has developed the greatest 

 variety both of genera and species. On the heights 

 of the Peruvian Andes, from the snows of the Chilian 

 Cordillera to the shores of the Pacific, as well as on 

 the plains of Argentaria and Uruguay, the botanist 

 is everywhere charmed by the brilliant flowers of 

 numerous species of true Verbena. In the warmer 

 zone the allied genus Lippia becomes predominant, 

 and displays an equal variety of aspect ; but in Chili 

 especially we find a number of plants very different 

 in aspect, although nearly allied in structure to the 

 familiar types. The plant of the Rio Colorado — 



