CERRO SAN CRISTOBAL. 157 



one thousand feet above the valley of the Mapocho. 

 We crossed that stream by a very massive bridge, 

 constructed to resist the formidable flood poured 

 down the channel after heavy rains, and for about 

 three miles followed the right bank along a rough 

 road deep in the sand formed by the disintegration of 

 the volcanic rocks. We were glad to leave our 

 vehicle at some mills at the foot of the hill, and spent 

 some three hours very agreeably in clambering up 

 and down the rough slopes. The shrubs were much 

 the same as those which I afterwards saw elsewhere 

 in similar situations, but I was fortunate in being 

 introduced to them by one so familiar with the flora 

 as my excellent companion. Among these, as well as 

 the herbaceous plants, the Compositce prevail over 

 every other natural order. Two common species 

 belong to the tribe of Mutisiacea, unknown in Europe, 

 and almost confined to South America. The bushy 

 species of Baccharis, a genus very widely spread in 

 the New World, but not known elsewhere, were also 

 very common. An acacia {A. Cavenid) approached 

 more nearly to the dimensions of a tree. It has stiff, 

 spreading, and very spiny branches, and is widely 

 spread throughout the drier parts of temperate South 

 America. Among the few herbaceous plants in 

 flower I was fortunate in seeing the pretty Gynopleura 

 linearifolia. This belongs to a tribe of the passion- 

 flower family, very distinct in habit and appearance, 

 which has been by some eminent botanists ranked as a 

 distinct natural order under the name Males her biacem. 

 It includes only two genera with ten or twelve species, 

 all exclusively natives of Chili or Peru. 



