268 VEGETABLE ZONES ON THE PAMPAS. 



Yet the mirage has been frequently observed 

 on the Llanos and the Pampas, those immense 

 plains which stretch far beyond the limits of the 

 visible horizon, and concerning which, as affording 

 peculiar features in transatlantic scenery, we shall 

 proceed to offer some closing observations. The 

 Pampas are by far the most extensive ; lying on 

 the eastern side of the Andes, and extending from 

 their foot to the shores of the vast Atlantic ; and 

 as the sides of lofty mountains present different 

 zones of plants, so remarkable differences of vegeta- 

 tion are apparent throughout these plains. The 

 ground, on leaving Buenos Ayres, is covered for 

 nearly one hundred and eighty miles with clover and 

 thistles ; this is the first division, beyond which an 

 immense prairie of long grass extends to, at least, 

 four times the distance, and is terminated by a beau- 

 tiful region of evergreen trees and shrubs, reaching 

 to the foot of the Cordilleras. These three divisions 

 are entirely distinct ; the trees and shrubs which 

 diversify the last, never encroach upon the prairie : 

 their seeds, or cones, scattered by the wind, effect no 

 lodgment amid the waving grass, which seems to be 

 without a weed ; while in the woody region such 

 beautiful order prevails in the growth of the trees, 

 that a horseman may gallop between them in every 

 direction. The district of clover and large thistles 

 varies, on the contrary, at different seasons of the 

 year. During winter it presents the appearance of 

 an immense clover field, over which herds of wild 

 cattle graze in unrestrained liberty. As spring 

 advances the clover disappears, and the thistles, 

 which began to lift their heads above the herbage, 



