286 OUTLINE OF PLANT GEOGRAPHY 



The Cinchona region has a flora of the same general type as that 

 of the Amazonian forest, and a good many of the same species. 

 Bamboos and other giant grasses are a feature of this region, 

 among them the giant arrow-grass (Gynerium saccharides), re- 

 lated to the familiar "pampas-grass" of the gardens, but sometimes 



30-40 feet high. 



There are many orchids, but mostly inconspicuous species. 

 The richest collecting grounds for showy orchids are further 

 north in the mountains of Colombia, and Central America, from 

 which come many of the choicest ornaments of our conserva- 

 tories. The many species of Cattleya, Odontoglossum and On- 

 cidium, and other extensively cultivated orchids, come from these 



countries. 



Exeept in the higher altitudes, the trees and shrubs of the moun- 

 tain forest belong to the same families as those dominating the 

 forest lower down, e. g., Rubiaceae, Leguminosae, Myrtaeeae, 

 Malpighiaeeae, etc. At higher elevations, however, temperate 

 genera occur, and at the highest altitudes there is a distinct alpine 

 flora. In the cool highlands we may find such familiar northern 

 plants as brambles, mallows, chick-weed, huckleberries, pig-weed 

 (Chenopodium), Geranium, catch-fly and a good many others; 

 but there are also certain distinctly Andean genera, like Fuchsia, 

 and Calceolaria, while the sub-alpine flowers including gentians, 

 valerian, paint-brush (Castilleia) and lupins, remind one of the 

 sub-alpine flora of the Californian mountains. 



The western slopes of the Andes are much dryer, and as Spruce 

 say< "The Amazon side of the Andes is incomparably richer than 

 the Pacific side." The former has a continuous rainy season with 

 little variation in temperature, while the Pacific slope has a long 

 dry season, and much of the coastal part of Peru, Ecuador and 

 northern Chile is an absolute desert where rain is almost unknown, 

 and except along the streams descending from the mountains, 

 vegetation is often completely absent. 



The writer's first-hand impressions of the equatorial South 

 American vegetation are derived from brief visits to Panama, 

 Guiana, and Trinidad, where, however, the vegetation is very 

 much the same as that of the Para district of the Amazon. 



The coast of the Guianas is mostly low and swampy, and the 

 tide extends for a long way up the rivers, whose lower reaches 



