138 



DISTRIBUTION OF PLANTS. 



Along the margin of the accumulated snow, the slope and con- 

 cavities were for some distance moistened by the slight occasional 

 melting. The vegetable growth here differed widely from that in the 

 Desert, presenting only the usual Alpine character; with many points 

 of agreement with Terra del Fuego, and species of plants that at first 

 seemed identical, but on closer examination, proved distinct. Grasses 

 occurred amid this moistened Alpine growth, especially in clefts of 

 rocks ; and proved, as in Terra del Fuego, to belong to familiar 

 European and Northern genera. 



But our guide would not permit us to linger, pointing to the threat- 

 ening weather ; as a fall of snow would render it difficult to keep the 

 path on our way back. We therefore set out before sunrise. After 

 re-crossing the ridge, and reaching the margin of the wide mountain- 

 valley, the danger was over, and we sent on the guide with the horses. 

 Mr. Dana being desirous of examining the rocks, which were exposed 

 at intervals along this margin, we proceeded at about the same eleva- 

 tion for some miles Southwest. 



The following plants were found growing in the Alpine region of 

 the Chilian Andes, above the elevation of ten thousand feet : 



Ranunculus (No. 25); leaves multifid, the segments linear. In moist places, along the 



margin of the bank of accumulated snow; rare. 

 Cardamine (No. 13) ; one to two inches high. In moist places, along the margin of the 



bank of snow. 



Sagina (No. 3); diffuse, leafy; the leaves obtuse; the flowers small. In moist places, 



along the margin of the bank of snow. 

 (Colobanthus? No. 3); near sp. of Terra del Fuego. Cespitose; flower on a long, naked 



pedicel, but the calyx five-cleft. Along the margin of the bank of snow. 

 Cerastium (No. 11). Intermingled in the beds of spinescent plants, and sheltered by 



them in the Desert. 



Nov. gen. Legum. (No. 2). Densely cespitose; having branching trifid spinescent phyl- 



lodia in place of leaves; the calyx-teeth pointed; pod short, rhomboidal, smooth, 



shining, pointed, one-seeded. Growing in cake-like beds in the upper portion of the 



Desert, towards the snow. 

 Astragalus? (No. 20). Diminutive, appressed to the ground; stipules large ; leaflets in 



five pairs. In the lower portion of the Alpine Desert. 

 Adesmia (No. 5). Cespitose, growing in beds two or three inches high, the terminal 



branching thorn included; leaflets in two pairs, large. Growing in the upper portion 



of the Desert, towards the snow. 

 Montia (fontana? No. 1). In moist places, along the margin of the bank of snow. 

 Gen. (Portulacac. ? No. 1). Habit of Cerastium, but the leaves alternate ; sepals two ; 



capsule coriaceous, three-valved. Intermingled in the beds of spinescent plants, and 



sheltered by them in the Desert. 



