AUSTRAL-AMERICAN REGIONS, 



135 



Nov. gen. Phytolaccac. (No. 1) ; compare P. drastica of Poeppig. The flowers green, 



Pyrola-like ; the berries red. In the upper portion of the region, growing in the shade 



of detached blocks or boulders. 

 Quinchamaliuni Chilense, (bis No. 1 lower down); small green flowers. 

 Euphorbia (bis No. 46 lower down). Eight inches high; the leaves obovate, entire. 

 Ephedra (bis No. 1 Patagonia, and lower down in Chili). Stunted, and more branched 



than when growing below in the level country. 

 Sisyrinchium (No. 15). A withered stem only ; the spathes broad. Found by C. P. 



? (No. 16) ; habit of Lygeum. Found by Mr. Brackenridge. 



Alstroemeria (No. 3). Four to six inches high; bearing a large, upright flower. In the 



shade of detached blocks or boulders. 

 Isolepis (bis No. 8 lower down). Two to three inches high, cespitose ; a lateral spikelet. 

 Stipa? (No. 18). The corolla-glumes red; awn widely plumose at base. 

 Agrostis (No. 32). Found by Mr. Brackenridge. 

 Hordeum ? (No. 7). In the upper portion of the region. 



6. The Alpine Region of the Chilian Andes. 



At noon we reached the head of the wide raountain-valley, and 

 entered the Alpine region ; commencing on the brow of the branching 

 ridge. Our party here separated; Mr. Dana and myself continuing 

 on, accompanied by a guide (of Aboriginal parentage). The acclivity 

 gradually becoming more gentle, in half an hour we crossed the 

 rounded summit of the ridge ; we then turned Northeast, and fol- 

 lowed the crest, all the way perceptibly ascending. 



The vegetable growth becoming more and more depressed, at length 

 separated into small condensed beds, that soon became widely de- 

 tached ; and we sometimes rode an eighth of a mile over bare soil, 

 loose and dry, and interspersed angular fragments of rock, without 

 passing a single cake of herbage. 



Accustomed to associate moisture with mountain-tops, I had never 

 dreamed of the existence of an Alpine Desert : but here, aridity 

 kept increasing with the cold ; the stillness awful and universal, as 

 though we had entered the domain of silence. From the crest of the 

 mountain-ridge of La Dessa, we were looking across an abyss upon 

 the Andes ; their altitude doubled, the weather clear, and the ex- 

 treme snowy peaks in sight. North and South, hardly less than three 

 hundred miles apart. 



In the North, out of the endless series of crowded, crest-like sum- 

 mits, Aconcagua rose above the rest, steep and inaccessible to its 

 pointed apex ; and a further slender and faintly visible streak, which 



